where and when in which state is gold found in nature​

Answers

Answer 1

notable states in the United States where gold is found include California, Alaska, Colorado, Nevada, and South Dakota.

when:(gold rushes)

   California (1848-1855)

   Colorado (1858-1861)

   Alaska (1896-1899)

   South Dakota (1874-1877)

   Georgia (1828-1849)

   Montana (1862-1864)

   Nevada (1859-1864)

   Oregon (1851-1861)

   North Carolina (1799-1848)

Answer 2
Gold is primarily found as the pure, native metal. Sylvanite and calaverite are gold-bearing minerals. Gold is usually found embedded in quartz veins, or placer stream gravel. It is mined in South Africa, the USA (Nevada, Alaska), Russia, Australia and Canada.

Related Questions

During a course of reaction, can only one activated complex be formed for a particular type of reaction?​

Answers

No, during a course of reaction, multiple activated complexes can be formed for a particular type of reaction. An activated complex is a short-lived, high-energy intermediate state that occurs during a chemical reaction.

What is  energy ?

Energy is a fundamental concept in physics that describes the capacity of a physical system to do work or produce a change. It is a property of matter and radiation and can be converted from one form to another. There are various types of energy, including kinetic energy (energy of motion), potential energy (energy due to position or configuration), thermal energy (energy due to the temperature of a system), chemical energy (energy stored in the bonds between atoms and molecules), and nuclear energy (energy stored in the nucleus of an atom). The unit of energy is the joule (J) in the SI system.

To know more about energy visit :

https://brainly.com/question/11399976

#SPJ1

how many millilitres of 0.200 m naoh are required to neutralize 20.0 ml of 0.100 m hcl?

Answers

10.0 mL of 0.200 M NaOH is required to neutralize 20.0 mL of 0.100 M HCl.

To calculate the milliliters of 0.200 M NaOH that are required to neutralize 20.0 mL of 0.100 M HCl, the following steps are used:

Step 1: Write the balanced chemical equation 2 NaOH (aq) + H2SO4 (aq) → Na2SO4 (aq) + 2 H2O (l)

Step 2: Determine the number of moles of the HCl solution: Concentration = 0.100 MVolume = 20.0 molarity = moles / LTherefore, Moles of HCl = (0.100 mol/L) × (20.0 mL / 1000 mL/L) = 0.00200 moles of HCl

Step 3: Determine the number of moles of NaOH needed to neutralize the HCl.The balanced equation shows that one mole of NaOH reacts with one mole of HCl.Therefore, Moles of NaOH = Moles of HCl = 0.00200 moles of NaOH

Step 4: Determine the volume of NaOH needed to reach the moles of NaOH needed to neutralize the HCl.Concentration = 0.200 MVolume = ?Molarity = moles / LTherefore, Volume = Moles / Molarity = 0.00200 moles / 0.200 M = 0.0100 L = 10.0 mL.

Learn more about molarity here:

https://brainly.com/question/8732513

#SPJ11

If a sample of radioactive isotopes takes 60 minutes to decay from 200 grams to 50 grams, what is the half-life of the isotope

Answers

The radioactive atom in this sample has a half-life of about 138.6 minutes.

The half-life of a radioactive isotope is the time required for half of the atoms in a sample to decay. The half-life of an isotope depends on its specific decay rate, which is determined by its nuclear properties.

In this case, the sample of radioactive isotopes decays from 200 grams to 50 grams over a period of 60 minutes. We can use this information to calculate the half-life of the isotope using the following equation:

N = N₀ x [tex](1/2)^(t/T)[/tex]

where N is the final amount of the isotope (50 grams), N₀ is the initial amount of the isotope (200 grams), t is the time elapsed (60 minutes), and T is the half-life of the isotope (in minutes).

Substituting the given values into the equation, we get:

50 = 200 x [tex]1/2^{(60/T)}[/tex]

Dividing both sides by 200 and taking the natural logarithm of both sides, we get:

ln(1/4) = -60/T

Solving for T, we get:

T = -60 / ln(1/4) ≈ 138.6 minutes

Therefore, the half-life of the radioactive isotope in this sample is approximately 138.6 minutes.

To learn more about isotopes refer to:

brainly.com/question/5357969

#SPJ4

Calculate the [H3O+] and the pH of a 0.140 M H3C6H5O7 solution.

Answers

The [H₃O+] and the pH of a 0.140 M H₃C₆H₅O₇ solution is [H₃O+] = 1.49 ×[tex]10^-3[/tex]M, and pH = -log[H₃O+] = 2.83.

H₃C₆H₅O₇ is a weak acid, so we need to use the acid dissociation constant (Ka) to calculate the [H₃O+] and pH of its solution. The Ka for H₃C₆H₅O₇ is 6.3 × [tex]10^-5.[/tex]

The balanced chemical equation for the dissociation of H₃C₆H₅O₇ in water is:

H₃C₆H₅O₇ + H2O ⇌ H3O+ + H₃C₆H₅O₇-

At equilibrium, let x be the concentration of H₃O+ and H₃C₆H₅O₇-. Then:

Ka = [H₂O+][ H₃C₆H₅O₇-] / [H3C6H5O7]

Ka = [tex]x^2[/tex]/ (0.140 - x)

Assuming that x is much smaller than 0.140, we can simplify this equation to:

[tex]x^2[/tex] = Ka × 0.140

x = √(Ka × 0.140)

x = √(6.3 × [tex]10^-5[/tex]× 0.140)

x = 1.49 × [tex]10^-3[/tex]M

solution is a homogeneous mixture of two or more substances that are uniformly dispersed throughout the mixture. The substance that is present in the largest amount is called the solvent, and the substances that are dissolved in the solvent are called solutes.

Learn more about solution here:

https://brainly.com/question/30665317

#SPJ4

What is the wavelength (in nm) of the photon absorbed for a transition of an electron from n_initial=1 that results in the least energetic spectral line in the ultraviolet series of the H atom?
be sure your answer has the correct number of significant figures. note: reference the fundamental constants and si prefixes tables for additional infor

Answers

The wavelength (in nm) of the photon absorbed for a transition of an electron that results in the least energetic spectral line in ultraviolet series of the H atom is 121.6 nm.

This is derived from the Rydberg formula, which relates the energy levels of an electron in an atom to the wavelength of light emitted or absorbed in the process of an electron transitioning from one level to another. Using the equation E_n = -13.6 eV/n^2, we can find the energy level of the n_initial=1 electron state to be -13.6 eV.

Subtracting this value from the energy level of the n=2 state, which is -3.4 eV, we obtain the energy difference between the two states as 10.2 eV. Using E = hf = hc/λ, where h is Planck's constant (6.626 x 10^-34 Js), c is the speed of light (2.998 x 10^8 m/s), and f is the frequency of the absorbed photon, we can calculate the wavelength of the photon as 121.6 nm.

Know more about Rydberg formula here:

https://brainly.com/question/13185515

#SPJ11

 Please help
The enthalpy of vaporization for water is 40.7 kJ/mol. Water has a vapor pressure of 101.3 ka at 100.0 °C. Using the Clausius-Clapeyron equation, what is the vapor pressure for methanol at 70.0
°C? Give your answer in kPa, to the first decimal point.

Answers

The Clausius-Clapeyron equation is:

ln(P₂/P₁) = -ΔH_vap/R * (1/T₂ - 1/T₁)

where P₁ and T₁ are the vapor pressure and temperature of the first substance (water), P₂ and T₂ are the vapor pressure and temperature of the second substance (methanol), ΔH_vap is the enthalpy of vaporization, R is the gas constant (8.314 J/mol*K).

Using the given values:

P₁ = 101.3 kPa
T₁ = 100.0 + 273.15 = 373.15 K
ΔH_vap = 40.7 kJ/mol
R = 8.314 J/mol*K

We need to solve for P₂ at T₂ = 70.0 + 273.15 = 343.15 K.

ln(P₂/101.3) = -40700 J/mol / (8.314 J/mol*K) * (1/343.15 K - 1/373.15 K)

ln(P₂/101.3) = -3.948

P₂/101.3 = e^(-3.948)

P₂ = 16.1 kPa

Therefore, the vapor pressure for methanol at 70.0 °C is 16.1 kPa (to the first decimal point)

the role of sulfuric acid in the synthesis of pyrylium bisulfate is to

Answers

The role of sulfuric acid in the synthesis of pyrylium bisulfate is to create a favorable reaction condition by promoting protonation.

Pyrylium bisulfate is an organic compound with the formula C5H5SO4H. It is a white crystalline powder that has an interesting history in the area of color chemistry. The compound was first synthesized by Henry Gilman and Edith Roberts in 1937.
Pyrylium bisulfate is synthesized through the reaction of pyridine with sulfuric acid. In the reaction, the pyridine molecule reacts with a sulfuric acid molecule to produce pyrylium bisulfate as a result. The chemical reaction can be expressed as follows:
C5H5N + H2SO4 → C5H5SO4H + H2O
Sulfuric acid plays an important role in this reaction as it acts as a catalyst. The catalyst helps to promote protonation of the pyridine molecule. This protonation is essential to the reaction because it allows the pyridine to react with the sulfuric acid. When the pyridine is protonated, it is more reactive and can easily react with the sulfuric acid.
The reaction between pyridine and sulfuric acid results in the formation of a pyridinium cation. This cation then reacts with another sulfuric acid molecule to produce pyrylium bisulfate. The process is repeated until the desired amount of pyrylium bisulfate is formed.
In summary, the role of sulfuric acid in the synthesis of pyrylium bisulfate is to create a favorable reaction condition by promoting protonation. This protonation allows the pyridine molecule to react with sulfuric acid and form pyrylium bisulfate as a result.

for such more question on sulfuric acid

https://brainly.com/question/10220770

#SPJ11

is it ever possible to have a strong acid with a ph that is higher than a weak acid?

Answers

No, a strong acid cannot have a pH that is greater than that of a weak acid with the same concentration. A solution's acidity is determined by its pH, with lower pH values suggesting higher acidity.

When an acid is dissolved in water, strong acids totally dissociate into ions, whereas weak acids only partially do so. The concentration of hydrogen ions (H+) in the solution will still be higher than that of a strong acid of the same concentration, even if a weak acid has only partially dissociated. Because an acid's propensity to give protons determines how strong it is, an acid with a larger concentration of H+ ions in solution will have a lower pH value.A weak acid with the same concentration cannot have a pH that is higher than a strong acid. When a weak acid partially dissociates into ions, it will have a lower concentration of H+ ions and a higher pH than a strong acid of the same concentration. The concentration of hydrogen ions in a solution affects its pH.

learn more about strong acid  here:

https://brainly.com/question/31143763

#SPJ4

How many moles of gas does it take to occupy 120 liters at a pressure of 2.3 atmospheres and a temperature of 350 K?
Remember:R=0.0821 L•atm/mol k
A. 9.6 mol
B. 3.4 mol
C. 4.7 mol
D.0.79 mol

Answers

Answer:

A - 9.6 mol.

Explanation:

Took the test.

a) Is the energy absorption associated with bands in an infrared spectrum of higher or lower energy than the lines appearing in a visible line spectrum. Explain?
b) Identify the type of energy transition occuring in a molecule that causes a band to appear in an infrared spectrum.
c) Identify the type of energy transition occuring in an atom that causes a line to appear in a visible line spectrum.

Answers

a) The energy absorption associated with bands in an infrared spectrum is of lower energy than the lines appearing in a visible line spectrum because infrared light has a longer wavelength than visible light, meaning that the energy required for the absorption is lower. b) The type of energy transition occurring in a molecule that causes a band to appear in an infrared spectrum is a transition from one vibrational state to another. c) The type of energy transition occurring in an atom that causes a line to appear in a visible line spectrum is an electronic transition.


a) The energy absorption related to bands in an infrared spectrum is lower in energy than the lines appearing in a visible line spectrum. The energy absorption in infrared spectrum ranges from [tex]4000 cm^{-1} to 400 cm^{-1}[/tex] . The visible spectrum of lines comes from the emission spectra of atoms, and each line corresponds to a particular energy level transition in an atom. The energy absorption related to bands in an infrared spectrum is lower in energy than the lines appearing in a visible line spectrum. The frequency of energy is higher when electromagnetic radiation has a shorter wavelength (or greater frequency). Electromagnetic radiation is characterized by frequency and wavelength, which are inversely proportional. Thus, radiation with a greater frequency has a shorter wavelength, whereas radiation with a lower frequency has a longer wavelength.

b) When a molecule absorbs energy, it undergoes an energy transition from one energy level to another. Infrared absorption spectroscopy measures the vibrations of molecular bonds, which correspond to the transitions between the vibrational energy levels of a molecule. Molecular vibrational energy is absorbed when infrared radiation is absorbed. When the energy absorbed is equal to the difference between the vibrational energy states of the molecule, an infrared band is observed.

c) Visible line spectra are produced when electrons transition from a higher energy level to a lower one, causing a photon of light to be emitted. When an atom absorbs energy, such as from a flame, a plasma arc, or an electrical discharge, its electrons can be promoted to higher energy levels. When the electrons relax back to the ground state, they emit energy in the form of electromagnetic radiation. The emitted light occurs in different regions of the visible spectrum, with each color corresponding to a specific energy level transition of the atom.

To know more about the infrared spectrum, click on the below link:

https://brainly.com/question/29796312

#SPJ11

which example is an exothermic reaction? responses dissolving sugar in water dissolving sugar in water melting ice melting ice dissolving ammonium nitrate in water to cool the water dissolving ammonium nitrate in water to cool the water condensation

Answers

The correct option is dissolving ammonium nitrate in water to cool the water.

Among the given options, the example of an exothermic reaction is dissolving ammonium nitrate in water to cool the water.

Exothermic reactions are chemical reactions that release heat energy into the surroundings. As a result, the products have less energy than the reactants. Dissolving ammonium nitrate in water to cool the water is a good example of an exothermic reaction because it releases heat energy and cools down the surrounding water.

When ammonium nitrate dissolves in water, it releases heat, causing the temperature of the water to decrease. The reaction is exothermic because it releases heat to the surroundings. Dissolving sugar in water and melting ice are examples of endothermic reactions because they absorb heat energy from the surroundings.

Therefore, the correct answer is the option of dissolving ammonium nitrate in water to cool the water.

To learn more about exothermic reactions refer - https://brainly.com/question/10373907

#SPJ11

if 1.00 kg of zn reacted with excess sulfur, how much energy would be released? enter your answer as a positive value.

Answers

Therefore, the energy released is 3168.92 kJ.

the enzyme pyruvate dehydrogenase generates _____ acetyl coa, _______ nadh, and _____ co2 molecule.

Answers

The enzyme pyruvate dehydrogenase generates 1 acetyl coA, 2 NADH, and 1 CO2 molecule.

Pyruvate dehydrogenase (PDH) is a complex enzyme located in the mitochondria of eukaryotic cells and is responsible for catalyzing the oxidation of pyruvate to Acetyl-CoA. This oxidation is the first step of the Krebs Cycle, the metabolic pathway by which most organisms obtain energy from carbohydrates.

During this oxidation, PDH converts 1 molecule of pyruvate into 1 molecule of Acetyl-CoA, 2 molecules of NADH, and 1 molecule of CO2.
PDH is composed of 3 components, each with its own unique function: E1, E2, and E3.

E1 is responsible for the decarboxylation of pyruvate, producing CO2.

E2 then forms the thioester bond between acetyl and CoA, producing acetyl-CoA. Finally,

E3 oxidizes NADH, producing 2 molecules of NADH.

This series of reactions allows for the energy stored in carbohydrates to be efficiently released, providing the cells with the energy they need to function. This is why the enzyme PDH is so important for the survival of most organisms.

for such more question on pyruvate dehydrogenase

https://brainly.com/question/29997944

#SPJ11

how to use edurus and maxima potions simultaneously?

Answers

It is not possible to use Edurus and Maxima potions simultaneously in the Harry Potter world.

According to the books and movies, each potion has a specific purpose and cannot be combined for a stronger effect. Edurus is a healing potion that can mend broken bones and heal other injuries, while Maxima is a spell that amplifies the strength of a spell. Therefore, the two have entirely different functions and cannot be used together.However, in some Harry Potter video games, it may be possible to use these potions together. Still, it is not consistent with the canon of the books and movies. In conclusion, it is not possible to use Edurus and Maxima potions simultaneously in the Harry Potter universe, as they serve two entirely different functions.

For more questions on Edurus

https://brainly.com/question/30766927

#SPJ11

when working with acids, which of the following is the proper way to dilute these chemicals? group of answer choices place acid in a graduated cylinder then add water to the correct volume none of the above add water to the acid in a beaker add the acid to water

Answers

Adding the acid to water is the proper way to dilute chemicals. Begin by measuring the correct volume of acid in a graduated cylinder. Next, pour the acid into a beaker containing the correct volume of water. Finally, stir the solution until it is fully mixed.

What are acids?

Acids are strong chemical compounds. When working with acids, it is important to dilute them in the correct manner to prevent harm to oneself or the surrounding environment.

The correct method of dilution for acids is to add the acid to water, not the other way around. This is because adding water to acid can cause an exothermic reaction that releases heat and may cause the acid to splash and burn you.

When diluting acids, be sure to add the acid to water slowly and stir continuously to prevent splashing and heat generation. Therefore, the correct answer is to add the acid to water.

Learn more about Acids here:

https://brainly.com/question/29796621


#SPJ11

According to octet rule, atoms tends to acheive _____ electrons in the outermost shell.A sixB fourC eightD one

Answers

According to the octet rule, atoms tend to achieve eight electrons in the outermost shell. The reason behind this tendency is that the atoms try to achieve a stable electronic configuration, which is similar to the noble gases, whose electronic configuration is stable.

The arrangement of an atom's or molecule's (or other physical structure's) electrons in their atomic or molecular orbitals is known as the electron configuration in atomic physics and quantum chemistry. For instance, the neon atom's electron configuration is 1s2 2s2 2p6, which means that 1, 2 and 6 electrons, respectively, are present in each of the 1s, 2s, and 2p subshells. According to electronic configurations, each electron moves individually within an orbital while being surrounded by an average field produced by all other orbitals. Slater determinants or configuration state functions are used to mathematically describe configurations. For systems with a single electron, the laws of quantum mechanics state that each electron configuration has a specific amount of energy, and that under certain circumstances, electrons can switch between configurations.

Electronic configuration is the distribution of electrons in various shells or orbitals. According to the octet rule, the outermost shell of the atoms must contain eight electrons for the atom to be stable. The octet rule is one of the essential rules that govern the formation of chemical compounds. It states that atoms tend to combine with other atoms in such a way that they will have eight electrons in their outermost shell or valence shell, which makes them more stable. The octet rule explains that the atoms combine or share electrons to form a compound in a way that each atom achieves eight electrons in its valence shell.

The sharing or transfer of electrons from one atom to another results in the formation of ionic or covalent bonds, which is the basis of chemical reactions.

For more such questions on electronic configuration , Visit:

https://brainly.com/question/26084288

#SPJ11

which solution has the highest boiling point at standard pressure? (1) 0.10 m mgcl2(aq) (2) 0.10 m mgso4(aq)

Answers

The solution with the highest boiling point at standard pressure is the one with the highest concentration of solutes, which increases the boiling point of the solution. In this instance, the answer is 0.10 M MgCl2(aq).

What is boiling point and standard pressure?

Boiling point: The boiling point of a solution is the temperature at which the vapour pressure of the solution equals the external pressure, allowing the solution to boil.

Standard pressure: One atmosphere of pressure is defined as the standard pressure.

A solution has the highest boiling point at standard pressure (1 atm) when it has the greatest concentration of solutes (molarity).

Which solution has the highest boiling point at standard pressure?

MgCl2 will have the greatest boiling point at a normal pressure since it has the most solute concentration.

The boiling point of a liquid is raised when solutes are added to it because the vapour pressure of the solution is lowered, thus more energy is required to break the intermolecular forces between the solvent and solute particles.

The boiling point of the solution rises as more solute is dissolved in the solvent, and the solvent-solute intermolecular forces become stronger, thus increasing the boiling point.

As a result, the 0.10 M MgCl2(aq) solution has the greatest boiling point among the options given.

for more information about boiling point at standard pressure refer here:

https://brainly.com/question/238983?

#SPJ11

Carbon dioxide gas is collected in a laboratory experiment to determine the molar mass of the compound. At 294 Kand 1.01 atm, 1.008 grams of co2 was collected when a 500 mL flask was filled with the evolved co2. What is the experimental molar mass of co2? a. 41.5 g/molb., 44.0 g/mol c. 46.9 g/mol d 48.2 g/mol

Answers

The experimental molar mass of CO2 collected in a laboratory experiment is 44.0 g/mol.

When carrying out laboratory experiments, carbon dioxide gas is collected to determine the molar mass of the compound. When a 500 mL flask was filled with the evolved CO2 at 294 K and 1.01 atm, 1.008 grams of CO2 was collected. It is required to determine the experimental molar mass of CO2. To solve the problem, we will make use of the ideal gas law formula:

P.V = n.R.T Where,P = 1.01 atmV = 500 mL = 0.500 Ln = number of moles of CO2R = 0.0821 L.atm.K-1.mol-1T = 294 K Substituting the values in the formula, we get;1.01 atm × 0.500 L = n × 0.0821 L.atm.K-1.mol-1 × 294 K1.01 × 0.500 = n × 24.79n = (1.01 × 0.500) / 24.79n = 0.02039 moles of CO2. We know that the mass of CO2 that was collected is 1.008 grams.Therefore, the molar mass of CO2 = mass / number of moles = 1.008 g / 0.02039 mol = 49.38 g/mol

But, we know that CO2 has a molar mass of 44.01 g/mol. Hence, the value of 49.38 g/mol is not the experimental molar mass of CO2 and so, we have to calculate the experimental molar mass of CO2 as follows:Experimental molar mass of CO2 = mass / number of moles = 1.008 g / 0.02039 mol = 49.38 g/mol. Actual molar mass of CO2 = 44.01 g/mol.

Experimental error = | experimental value - actual value | / actual value × 100%.Substituting the values in the formula, we get;

Experimental error = | 49.38 - 44.01 | / 44.01 × 100%

Experimental error = 12.2% ≈ 12%.

Therefore, the experimental molar mass of CO2 is 44.0 g/mol (Option b).

More on molar mass: https://brainly.com/question/18879890

#SPJ11

what were the factors responsible for the change of dead organic matter into fossil fuels?

Answers

Given enough pressure, organic matter can also become natural gas. Heat and pressure are the two main forces that transform organic matter into fossil fuels.

Mark Brainliest please

Based on the same principles as above, classify the radioactive decays as alpha emission, beta emission, or electron capture.Alpha emission:Beta Emission:Electron Capture:-40K19-218Po84-226Ra88
-234Th90

Answers

For the given radioactive decays: ₄₀K¹⁹: Beta emission ₂₁₈Po⁸⁴: Alpha emission ₂₂₆Ra⁸⁸: Electron capture. Alpha particles are helium nuclei (2 protons and 2 neutrons) emitted from some unstable nuclei of elements.

What are gamma rays?

Gamma rays are a type of electromagnetic radiation, much like x-rays, visible light and radio waves. Gamma rays possess the highest frequency and the most energy of all types of electromagnetic radiation, and are created in the most extreme environments in the Universe. They are emitted from the nuclei of atoms  some natural events such as supernovae, and can range from very low energies to the highest energies of all electromagnetic radiation. Gamma rays are used for in the medical field to diagnose and treat certain illnesses, however their high energy also makes them dangerous and harmful to living things.

Why Does Radioactive Decay Occur?

Radioactive decay occurs when unstable atoms lose energy by emitting particles and/or radiation. Put simply, atoms become unstable and break apart to become more stable, and the process of releasing this energy is known as radioactive decay. Radioactive decay can be seen when certain elements spontaneously transform into other elements by emitting alpha particles, beta particles, or gamma radiation. Over time, these particles and/or radiation emitted cause the original atoms to become completely different elements.

To know more about alpha emission, visit:

https://brainly.com/question/28564218

#SPJ1

Match each equation for calculating heat lost or gained (q) during a process to its correct application. Drag statements on the right to match the left. Heating or cooling within a phase if moles are given C- q = nCAT Heating or cooling during a phase change D-a 9 = NAH change Heating or cooling within a phase if mass is given CHO q=mcAT

Answers

The correct match are: q = nCAT for Heating or cooling within a phase if moles are given, q = NAΔH for Heating or cooling during a phase change, and q = mcΔT for Heating or cooling within a phase if mass is given.

What is the heat loss during phase change?

q = nCAT is used to calculate Heat lost or gained when heating or cooling within a phase if moles are given. In this equation, n is the number of moles, C is the heat capacity of the substance, A is the temperature change.

q = NAΔH is used to calculate Heat lost or gained when heating or cooling during a phase change. In this equation, N is the number of moles, ΔH is the enthalpy of fusion or vaporization.

q = mcΔT is used to calculate Heat lost or gained when heating or cooling within a phase if mass is given. In this equation, m is the mass of the substance, c is the specific heat capacity of the substance, ΔT is the temperature change.

Learn more about Phase change here:

https://brainly.com/question/30270780

#SPJ11

a calorie is the commonly used unit of chemical energy. it is also the unit of

Answers

A calorie is the commonly used unit of chemical energy. it is also the unit of energy used to measure the energy content of food.

More on Calorie and Energy

Calorie (or kilocalorie) is a unit of measurement used to measure the energy content of food. It is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius.

One calorie is equal to the amount of energy required to raise the temperature of one gram of water by one degree Celsius.

Energy is a fundamental property of matter that can take many forms, such as electrical, thermal, chemical, nuclear, and mechanical energy.

Learn more about Calorie here:

https://brainly.com/question/1178789

#SPJ1

For each of the following precipitation reactions, calculate how many grams of the first reactant are necessary to completely react with 17.3 g of the second reactant.Part A2KI(aq)+Pb(NO3)2(aq)→PbI2(s)+2KNO3(aq)m = 17.3 gSubmitMy AnswersGive Up

Answers

17.264 g of 2KI (potassium iodide) is necessary to completely react with 17.3 g of Pb(NO3)2 in a precipitation reaction.

To calculate the mass of the first reactant required, we will use the mole concept.

Let's first write the balanced chemical equation.

A 2KI(aq) + Pb(NO₃)₂ (aq) → PbI₂(s) + 2KNO₃(aq)

We need to find the number of moles of Pb(NO₃)₂.

To do that, we will use the given mass of Pb(NO₃)₂ and its molar mass.

Molar mass of Pb(NO₃)₂ = 207.2 + 3(14.01) + 6(16) = 331.2 g/mol

Number of moles of Pb(NO₃)₂ = mass / molar mass = 17.3 / 331.2 = 0.052 moles

From the balanced chemical equation, we see that 1 mole of Pb(NO₃)₂ reacts with 2 moles of KI.

Therefore, the number of moles of KI required would be twice the number of moles of Pb(NO₃)₂.

The number of moles of KI required = 2 x 0.052 = 0.104 moles

To calculate the mass of KI required, we will use its molar mass.

The molar mass of KI = 39.10 + 126.90 = 166.0 g/mol

Mass of KI required = a number of moles x molar mass = 0.104 x 166.0 = 17.264 g

Therefore, 17.264 g of KI is required to completely react with 17.3 g of Pb(NO₃)₂.

Learn more about the calculation of grams here:

https://brainly.com/question/28902645

#SPJ11

how should you write the volume dispensed by a 5 ml volumetric pipet?

Answers

When writing the volume dispensed by a 5 ml volumetric pipet, it should be written as 5.00 mL.

A volumetric pipet is a laboratory instrument utilized to dispense very accurate and precise volumes of liquid. It is commonly used in analytical chemistry to make up solutions or to dilute stock solutions. Volumetric pipettes, also known as transfer pipettes or bulb pipettes, are single-volume liquid measuring instruments. They are meant to deliver a precise volume of liquid at a fixed temperature when the tip is slightly below the liquid surface.

It is important to write the volume with two decimal places to indicate the precision of the pipette.

Volumetric pipettes are utilized to prepare and dilute solutions. They are made of glass, with a round or conical end. They are intended to provide a precise volume of liquid, such as a certain number of milliliters or milligrams of a substance. Because of its accuracy, a volumetric pipet is used to create a standard solution.

For more such questions on volumetric pipet, click on:

https://brainly.com/question/28945018

#SPJ11

6.carbon 14 (14c) is unstable and has a half-life of 5730 years. an organic material buried in sedimentary rocks shows the parent-daughter ratio at 1:15 (meaning 1/16 parent, 15/16 daughter). assuming there was no daughter element at the time of burial, how old is this organic material?

Answers

The time of burial, the organic material will be about 34,880 years old.

What is the half-life of an element?

Half-life (t½) is the time which is required for a quantity of the substance to reduce to the half of its initial value. The term is commonly used in the nuclear physics to describe how quickly the unstable atoms or chemical elements undergo the radioactive decay or how long the stable atoms survive.


The amount of carbon 14 (14C) which can be found in the organic matter decreases due to the radiocarbon process. This process is also called as the radioactive decay. The half-life of carbon-14 (14C) is 5730 years. An organic material which was buried in the sedimentary rocks is examined, and it is the parent-daughter ratio is equal to about 1:15, indicating that there will be 1/16 of the parent element and 15/16 of the daughter element.

The organic material is supposed to have no daughter element at the time of burial. The age of this organic material is to be calculated. As given, the ratio of parent-daughter elements is 1:15 (1/16 parent, 15/16 daughter). After one half-life (i.e., 5730 years), half of the parent atoms will have decayed to the daughter atoms. Therefore, the parent-to-daughter ratio would be 1/32 parent, 31/32 daughter.

After the two half-lives (5730 + 5730 = 11460 years), 1/4 of the original parent atoms will remain, and the ratio will be 1/4 parent, 3/4 daughter. 1/4 is equal to 4/16. 4/16 + 12/16 = 16/16 = 1. This implies that the original amount of carbon 14 (14C) was about 4/16 of what it would have been if there were no daughter material present. To determine the age of the organic material, we may set up the following equation:

Parent to daughter ratio = 1:15 after 2 half-lives,

which is 5730 × 2 = 11,460.15/16 = (1/2)² × (1/16) = 1/64 (15 daughter atoms)

Therefore, there were originally 4 × 15 = 60 carbon 14 (14C) atoms.

1/64 = 1/60 × (1/2)n where n is the number of half-lives which have occurred.

Multiplying both sides by 60 × 64 gives: 1 = 64 × (1/2)n

Subtracting 64 from both sides gives: 63 = (1/2)n

Taking the natural logarithm of both sides gives: ln(-63) = n ln(1/2)

The value of ln(1/2) is -0.69315, so:

n = ln(-63)/ln(1/2)n = 6.0 half-lives have passed (rounded up).

Therefore, the organic material is 6 × 5730 = 34,380 years old.

Learn more about Half-life here:

https://brainly.com/question/24710827

#SPJ11

Consider the reaction NH4HS(s) ? NH3(g) + H2S(g)At a certain temperature, Kc = 8.5x10-3. A reaction mixture at this temperature containing solid NH4HS has [NH3] = 0.166 M and [H2S] 0.166 M. Will more of the solid form or will some of the existing solid decompose as equilibrium is reached?

Answers

The given equilibrium reaction is: NH4HS(s) ⇌ NH3(g) + H2S(g)

What is equilibrium reaction?

An equilibrium reaction is a reversible chemical reaction in which the forward and backward reactions occur at equal rates. At equilibrium, the concentrations of the reactants and products remain constant, and the rate of the forward reaction is equal to the rate of the backward reaction. In other words, the system is in a state of dynamic balance, where the concentrations of the reactants and products do not change over time.

The equilibrium constant, Kc, is given as 8.5 x 10^-3 at a certain temperature. At equilibrium, the concentrations of NH3 and H2S are given as [NH3] = 0.166 M and [H2S] = 0.166 M. We are asked to determine whether more of the solid NH4HS will form or whether some of the existing solid will decompose to reach equilibrium.

To solve this problem, we can first use the equilibrium constant expression to calculate the equilibrium concentration of NH4HS:

Kc = ([NH3] x [H2S]) / [NH4HS]

8.5 x 10^-3 = (0.166 M x 0.166 M) / [NH4HS]

[NH4HS] = (0.166 M x 0.166 M) / 8.5 x 10^-3

[NH4HS] = 3.25 M

The calculated concentration of NH4HS at equilibrium is 3.25 M, which is greater than the initial concentration of NH4HS. This indicates that more of the solid NH4HS will dissolve to form NH3 and H2S, rather than some of the existing solid decomposing. Therefore, the system will shift towards the product side to consume more NH4HS and form additional NH3 and H2S.

To know more about chemical compound visit :-

https://brainly.com/question/26487468

#SPJ1

12. The amount of H2, gas produced and the amount of copper metal dissolved in the reaction is directly proportional to the number of electrons transferred. A Faraday represents the charge carried by one mole of electrons. In Part 4 of this experiment you will determine Faraday's constant by measuring the amount of charge required per mole of electrons consumed or produced in each of the half-reactions. a) Write the half-reaction that occurs at the anode and that occurs at the cathode. b) The cathode is a copper wire, partly covered with plastic. Why is it important to make sure all the bare copper wire is inside the burette?

Answers

a) At the anode, the half-reaction is: 2H+ (aq) --> H2 (g) + 2e-  
   At the cathode, the half-reaction is: Cu2+ (aq) + 2e- --> Cu (s)

b) It is important to make sure that all the bare copper wire is inside the burette because the copper metal dissolved in the reaction is directly proportional to the number of electrons transferred. The copper metal is produced at the cathode when two electrons are transferred, so the entire copper wire must be in the burette to measure the amount of charge transferred and determine Faraday's constant.
The half-reaction that occurs at the anode is:Cu → Cu2+ + 2e- The half-reaction that occurs at the cathode is:H2 + 2e- → 2H+b) It is important to make sure all the bare copper wire is inside the burette because the electrons must be able to travel from the wire into the solution, and the wire must be completely submerged in the solution so that the electroplating reaction can occur properly.

For more such questions on Cathode

https://brainly.com/question/18621643

#SPJ11

which of the following relationships correctly express the clausius-clapeyron equation, which relates vapor pressure to temperature? select all that apply. multiple select question. a) ln p=-delta Hvap/R (1/T) +C
B) ln p=-delta Hvap/R (T2-T1)
C) ln p=-delta Hvap/nR T (1/T) +C
D) ln P1/P2=-delta Hvap/R (1/T2-1/T1)
E) ln P2/P1=-delta Hvap/R (1/T2-1/T1)

Answers

The Clausius-Clapeyron equation relates vapor pressure to temperature and the correct relationships are A, D, and E.

A: ln p=-delta Hvap/R (1/T) +C

D: ln P1/P2=-delta Hvap/R (1/T2-1/T1)

E: ln P2/P1=-delta Hvap/R (1/T2-1/T1)

Explanation:
The Clausius-Clapeyron equation relates vapour pressure to temperature. The relationships that correctly express the Clausius-Clapeyron equation are:A) ln p = -ΔHvap/R(1/T) + C (This equation shows that the natural log of the vapor pressure is inversely proportional to the temperature.)D) ln P1/P2 = -ΔHvap/R (1/T2 - 1/T1) (This equation shows that the natural log of the ratio of two vapor pressures is proportional to the reciprocal of temperature difference.)E) ln P2/P1 = -ΔHvap/R (1/T2 - 1/T1) (This equation is the same as equation D but the order of the pressure ratio is reversed.)Therefore, options A, D, and E correctly express the Clausius-Clapeyron equation which relates vapor pressure to temperature.

For more such questions on Clausius Clapeyron

https://brainly.com/question/24073811

#SPJ11

In modeling solid-state structures, atoms and ions are most often modeled as spheres. A structure built using spheres will have some empty, or void, spaces in it. A measure of void space in a particular structure is the packing efficiency, defined as the volume occupied by the spheres divided by the total volume of the structure.
Given that a solid crystalizes in a face centered cubic structure that is 4.10 {eq}\overset{o}{A} {/eq} on each side. How many total atoms are there in each unit cell?

Answers

There are the presence of atoms on eight corners of the face centered cubic lattice.

Void spaces are called as the gaps that lie within certain constituent particles. These void spaces are highly packed and they can be packed in 1D, 2D, or 3D. Such complexes are seen in many complexes such as coordination complexes. The face-centered cubic lattice which is called FCC is described as the arrangement in which there is an arrangement of atoms at corners as well as at the center of cell's each cube face. There is the presence of four atoms in one unit cell in such lattices. This is a cube with an atom on each corner and each face. It has atoms at each corner of the cube and six atoms at each face of the cube.

a= 5.01°A on each side.

To learn more about  face-centered cubic lattice

https://brainly.com/question/14927070

#SPJ4

The complete question is,

In modeling solid-state structures, atoms and ions are most often modeled as spheres. A structure build using spheres will have some empty, or void, space in it. A measure of void space in a particular structure is the packing efficiency, defined as the volume occupied by the spheres divided by the total volume of the structure.

Given that a solid crystallizes in a face centered cubic structure that is 5.01 A on each side.

How many total atoms are there in each unit cell?

According to Appendix D of your lab manual, how do you determine if a data point can be ignored when calculating the average in General Chemistry? By using the Q-test at 90% confidence By using the Q-test at 95% confidence By using the standard deviation at 90% confidence By using the standard deviation at 95% confidence The spectator ions in the reaction between aqueous perchloric acid and aqueous barium hydroxide are: HT, OH", C104, and Ba2+ CI04 and Ba2+ H+ and Ba2+ OH and CIO4 H+ and OH-

Answers

To determine if a data point can be ignored when calculating the average in General Chemistry, Appendix D of the lab manual recommends using the Q-test at 95% confidence. The Q-test is a statistical test that is used to determine if a data point is an outlier, or if it falls outside the expected range of values for the data set.

To use the Q-test, one must calculate the Q-value for each data point and compare it to the critical Q-value at the desired level of confidence. If the calculated Q-value is greater than the critical Q-value, then the data point is considered an outlier and can be excluded from the calculation of the average.

Regarding the second question, the spectator ions in the reaction between aqueous perchloric acid and aqueous barium hydroxide are H+ and ClO4-. These ions do not participate in the chemical reaction, but are present in the solution due to the dissociation of the reactants. The actual chemical reaction is the formation of insoluble barium perchlorate (Ba(ClO4)2) and water (H2O) through the combination of barium hydroxide (Ba(OH)2) and perchloric acid (HClO4), which are the only ions involved in the reaction.

To learn more about barium hydroxide refer to

brainly.com/question/30888146

#SPJ4

Other Questions
current flows into the ____. a. output terminal of a sinking b. input field device input terminal of a sinking dc c. input module input terminal of a sinking output field device d. all of the above T/F. The experiments in this lab session use the property of laser light collimation because in this way ligtht does not diverge (spread out) Question 3 of 10What would happen if households were removed from the circular flow ofgoods?A. Product markets would have nobody to buy their goods. B. Businesses would see an overall increase in profits. C. Businesses would have to pay more for their resources. D. Resource markets would increase the price of their products. true or false. testosterone administration induces a red shift in democrats enforce datacentric security, such as encryption, tokenization, and access control which of the following solutions should the security engineer recom What two technologies below are fully-implemented, 64-bit processors for use in servers and workstations? a. Centrino b. Itanium c. Xeon d. Core i7. If a breach relates to a fundamental term of the contract, it is called a total breach and the nonbreaching party is entitled to either: _______ or _______. (Choose two correct answers)be completely discharged from her obligationssuspend performance _____ Drugs that prevent the formation of the bacterial cell wall are: a) quinolones b) beta-lactams c) tetracyclines d) aminoglycosides e) macrolides. raised roadway markers on the roadway and shoulder are used to It is well documented that a typical washing machine can last anywhere between 5 to 20 years. Let the life of a washing machine be represented by a lognormal variable, Y = eX where X is normally distributed. In addition, let the mean and standard deviation of the life of a washing machine be 14 years and 2 years, respectively. [You may find it useful to reference the z table.] a. Compute the mean and the standard deviation of X. (Round your intermediate calculations to at least 4 decimal places and final answers to 4 decimal places.) b. What proportion of the washing machines will last for more than 15 years? (Round your intermediate calculations to at least 4 decimal places, "z" value to 2 decimal places, and final answer to 4 decimal places.) c. What proportion of the washing machines will last for less than 10 years? (Round your intermediate calculations to at least 4 decimal places, "z" value to 2 decimal places, and final answer to 4 decimal places.) d. Compute the 90th percentile of the life of the washing machines. (Round your intermediate calculations to at least 4 decimal places, "z" value to 3 decimal places, and final answer to the nearest whole number.) An economist claims that changes in information technology and unemployment insurance have reduced unemployment. Which of these changes affect frictional unemployment?A. both the changes in information technology and unemployment insuranceB. only the changes in information technologyC. only the changes in unemployment insuranceD. neither the changes in information technology nor the changes in unemployment insurance a context that helps to explain the development discussed in the excerpt is that, after 1920, americans were debating ___ It is given that quadrilateral abcd is a kite. we know that ad cd by the definition of . by the kite diagonal theorem, ac is to bd this means that angles aed and ced are right angles. we also see that ed ed by the property. therefore, we have that aed ced by . Terri Vogel, an amateur motorcycle racer, averages 129.77 seconds per 2.5 mile lap (in a 7 lap race) with a standard deviation of 2.26 seconds. The distribution of her race times is normally distributed. We are interested in one of her randomly selected laps. (Source: log book of Terri Vogel) Let X be the number of seconds for a randomly selected lap. Round all answers to 4 decimal places where possible. a. What is the distribution of X?XN(___________, _________). b. Find the proportion of her laps that are completed between 131.69 and 134.04 seconds________.c. The fastest 4% of laps are under__________seconds.d. The middle 70% of her laps are from seconds________ to_________ seconds. select all that apply when professionals with hub mvss listen to business presentations, they respond best to which of the following? (choose every correct answer.) multiple select question. language that presents several options brash, confident language bottom-line performance measures presentations that hold clear business logic a parachutist rate during a free fall reaches 132 feet per second. what is this rate in meters per second? at this rate, how many meters will the parachutist fall during 10 seconds of free fall. in your computations, assume that 1 meter is equal to 3.3 feet. (do not round your answer) Consider a square whose side-length is one unit. Select any five points from inside this square. Prove that at least two of these points are within squareroot 2/2 units of each other. kant rejected the utilitarian approach to morality because... group of answer choices a. it placed an insufficient priority on acting with integrity b. an action that is maliciously intended, may be deemed a moral act if it turns out that the consequences are good. c. it would hold the moral agent responsible for things that they can neither know with certainty nor control. d. it holds the highest good as happiness, which kant argued was asking too little of ourselves all of the above Four swimmers are training for a relay race. Each day they practice by swimming at least 1,600 yards total. The friends evenly divide the number of yards they swim.Write and solve an inequality to determine how many yards each friend will swim. Show all your work. look at this square: 2 mm 2 mm if the side lengths are tripled, then which of the following statements about its area will be true?