Answer:
D. All pure substances are molecules.
The correct statement about pure substances is; "All molecules are pure substances."
A pure substance contains exactly the same type of atoms. In a molecule, there can only be a particular combination of atoms.
For instance, a molecule of HCl can only contain chlorine and hydrogen atoms.
This means that every molecules are also pure substances.
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Calculate the amount of heat required to melt 2108 g of water. The enthalpy of fusion of water is ΔHfus=6.010 kJ/mol.
since the unit for the heat of fusion is kJ/mol, you're going to have to convert the grams into moles in order to cancel out the unit. After that, you can solve like normal.
Specific heat capacity of a substance is the amount of heat required to raise the temperature by one degree Celsius of one gram of a substance. Therefore, the amount of heat required to melt 2108 g of water is 703.7kJ.
What is Enthalpy?Enthalpy term is basically used in thermodynamics to show the overall energy that a matter have. Mathematically, Enthalpy is directly proportional to specific heat capacity of a substances.
Mathematically,
q = n ×ΔH
where
q = amount of heat=?
ΔH = enthalpy=6.010 kJ/mol
n = no of moles
n = w / M.M
w = given mass
M.M = molar mass
moles of water=2108 g ÷18g/mol
=117.1 mol
substituting all the given values in the above equation, we get
q =6.010 kJ/mol ×117.1 mol
=703.7kJ
Therefore, the amount of heat required to melt 2108 g of water is 703.7kJ.
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what is a cavity in your own words
Answer:
A cavity is a hole in a tooth that develops from tooth decay Cavities are permanently damaged areas in the hard surface of your teeth that develop into tiny openings or holes .They are caused by a combination of factors, including bacteria in your mouth, frequent snacking, sipping sugary drinks and not cleaning your teeth well.
these are in my own words
The unknown metal ion gave a yellow/orange flame test and no precipitate with ammonium carbonate. What is the unknown metal?
Answer:
Sodium
Explanation:
Explaining or interpreting the things you observe based on reasoning from what you already know is called a. observing. c. predicting. b. inferring. d. classifying.
Answer:
B. inferring
Explanation:
9. SI base units used in chemistry include
A. kilograms, liters, inches, and moles.
B. pounds, gallons, moles, and Fahrenheit.
C. kilograms, seconds, moles, and Kelvin.
D. pounds, gallons, moles, and Celsius.
Answer:
C. kilograms, seconds, moles, and Kelvin
1. A substance with 1 or 2 electrons in the valence shell is called what?
A. Insulator
B. Conductor
C. Molecule
D. Semiconductor
Answer:
B. Conductor
Explanation:
Please help me thank you
Explanation:
increases then decreases
Draw out a Simple electro Chemical Symbols in ions
Answer:
In redox reactions, electrons are transferred from one species to another. If the reaction is spontaneous, energy is released, which can then be used to do useful work. To harness this energy, the reaction must be split into two separate half reactions: the oxidation and reduction reactions. The reactions are put into two different containers and a wire is used to drive the electrons from one side to the other. In doing so, a Voltaic/ Galvanic Cell is created.
Explanation:
When a redox reaction takes place, electrons are transferred from one species to the other. If the reaction is spontaneous, energy is released, which can be used to do work. Consider the reaction of a solid copper (Cu(s)) in a silver nitrate solution (AgNO3(s)).
he AgNO3(s) dissociates in water to produce Ag+(aq) ions and NO−3(aq) ions. The NO3-(aq) ions can be ignored since they are spectator ions and do not participate in the reaction. In this reaction, a copper electrode is placed into a solution containing silver ions. The Ag+(aq) will readily oxidize Cu(s) resulting in Cu2+(aq), while reducing itself to Ag(s).
This reaction releases energy. When the copper electrode solid is placed directly into a silver nitrate solution, however, the energy is lost as heat and cannot be used to do work. In order to harness this energy and use it do useful work, we must split the reaction into two separate half reactions; The oxidation and reduction reactions. A wire connects the two reactions and allows electrons to flow from one side to the other. In doing so, we have created a Voltaic/ Galvanic Cell.
a 2.00 mL sample of a substance A has a density of 18.4g/mL and a 5.00 mL sample of substance B has a density of 35.5g/mL. do you have an equal mass of substances A and b?
this question made my brain hurt. please explain :(
Answer:
no
Explanation:
make use of this formula to find the mass of each sample.
m=density*volume
Hello I need help please
Answer:
A is the answer hope this helps if wrong I ont know
PLS HELP Quick!!!!!!!!!
Answer:
Bailee is incorrect. The mass of objects stay the same but the weight will change.
Explanation:
Mass is how much space something takes up, so that wouldn't change on the moon. The weight however would change because the gravitational pull on the earth is different from that on the moon.
I hope this helps!
Bailee explained that when traveling to the moon. The statement of Bailee is incorrect. The mass of the objects stays the same, but the weight will change. The correct option is B.
What is gravity?Gravity is a force that pulls all objects towards itself. It is present on the earth and in the galaxy. Gravity is the cause of all planets, and the sun and the moon stay in their own places.
The weight of items on the moon is equal to their weight on Earth, according to Bailee, thus he needs only bring a small amount of luggage. The mass is the quantity of matter. The mass never changes, only the weight changes of an object when they are on different planets.
Thus, the correct option is B. The mass of the objects stays the same, but the weight will change.
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What is the Ka expression for HCO3 ?
plz help!!
fill in the blank
Answer:
0.0325m = 3.25 cm
Explanation:
1m = 10-²cm
Answer:
3.25cm
Explanation:
a centimeter is just 1/100 of a meter
Pls help 10 points
Plsplsplspslspslspslsspsls
Which of the following is more soluble in water, methanol (CH3OH), or CH2I2(l).
Answer:
CH3OH
Explanation:
has hydroxide ions
Solubility has been the property of the substance to get dissolved to form the solution. Methanol (CH₃OH) is more soluble in water than Diiodomethane (CH₂I₂).
What is solubility?Solubility is best defined as the capability of the substance to get dissolved or dissociated into a solvent for the formation of the solution at a given temperature. The solubility of the various substances varies and is an important part of the mixture and solution.
Solubility in water has been the measure of the solute to get dissolved in water. The pressure and the temperature of the system directly affect the solubility of any substance in a solvent. Water is a polar molecule with hydrogen bonds in a great solvent that dissolves almost all the molecules like salt, sugar, etc.
Methanol is soluble in water as it contains hydrogen bonds as the intermolecular forces that interact with the polar water molecule by the virtue of the hydroxide and the hydrogen ions that show the molecular attraction and allows the molecule to get dissolved.
Therefore, methanol is soluble in water.
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How many molecules are their in o.5 mole of H2o
Answer:
There are 6.022x10^23 molecules
True or False
A sphere is a group of parts that work together as a whole.
False is the correct answer.
how can you use terms such as thermal energy, particles, motion, and flow to explain the movement of heat in our world
Answer: Thermal energy is the kinetic energy of particles and heat is the term used to describe how this energy may flow to other systems, such as in a radiator.
Explanation: Molecules have a level of kinetic energy that can be measured by temperature. Higher temperatures result in more rapid and frequent collisons of particles in motion. Heat is the term used to measure the quantity of vibration energy in a given system. The SI unit for heat energy is the Joule. The water molecules in a pot of boiling water have a kinetic energy sufficient for them to break away from other water molecules and become gaseous (boiling point). The heat energy in 1 liter of water at 95C can be calculated in terms of Joules/liter, based on the specific heat of water (e.g., in units of J/gC). This heat can flow to other systems. A home boiler heater unit heats water tha can be pumped around the house ehre it will flow from radiators into thje surrounding air.
Heat is the word used to explain how this energy may transfer to other systems, such as in a radiator, and thermal energy is the kinetic energy of particles.
What is thermal energy?
By virtue of its temperature, a system in a condition of thermodynamic equilibrium has thermal energy or internal energy. Unlike the energy of systems that are not in a state of thermodynamic equilibrium, thermal energy cannot be transformed into meaningful work as quickly.
For instance, the same fluid or solid in a thermodynamic equilibrium state with the same energy (as thermal energy) cannot do work unless it is combined with another substance at a different temperature, as in a heat engine. However, the same fluid or solid in a moving state with the same energy (as mechanical energy) can be converted to work in some mechanical device, such as a windmill or a waterwheel.
Therefore, heat is the word used to explain how this energy may transfer to other systems, such as in a radiator, and thermal energy is the kinetic energy of particles.
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what is the chemical formula of (Sodium hydroxide ) ??
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what is the chemical formula of (Sodium hydroxide ) ??
⚘ NaOHSodium hydroxide, Sodium oxidanide[tex] \: [/tex]
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Answer:
The formula of Sodinm hydroxide is NaOH
Hope it helps
4(a) Why doesn't the water flow out when the hand that presses the cardboard is removed? *
1. water inside glass is lighter
2. there is much water inside the glass
3. cardboard is supported by air pressure
4.
cardboard is strong enough to hold the water
How many centimeters are there in 5.44 meters?
Answer:
544 cm!
I hope this helped.
Answer:
The answer of your question is 544 cm
Explanation:
5.44 × 100
544 cm
The temperature of 150 mL of water is 25°C. What must happen for the temperature of the
water to increase to 35°C?
A. Thermal energy must be transferred to the water to increase the average kinetic
energy of the water molecules.
B. Thermal energy must be transferred from the water to decrease the average
kinetic energy of the water molecules.
C. Water must be removed to decrease the thermal energy.
D. More water must be added to increase the thermal energy.
Answer:D
Explanation:
How would life be different without penicillin
Answer:
Without new antibiotics, common infections and minor injuries could become life-threatening and major surgeries and chemotherapy impossible because the treatments we have been using for years are no longer effective.
which statement correctly contrasts science and psuedoscience
Answer:
The correct answer is Science is objective, whereas pseudoscience is subjective. Pseudoscience includes beliefs, theories, or practices that have been or are considered scientific, but have no basis in scientific fact. This could mean they were disproved scientifically, can't be tested or lack evidence to support them.
Explanation:
hope its help
thank you
What is the voltage for the equation CuCl2+Zn—> ZnCl2+Cu?
The standard voltage for the equation CuCl₂ + Zn —> ZnCl₂ + Cu is -1.1 Vol.
What is voltage?
Voltage is the pressure of the charged electrons in an electric circuit which pushes the electrons towards the switch, which makes the light illuminate. By Ohm's law, voltage is equal to current x resistance.
V = IR
The reaction is CuCl₂ + Zn —> ZnCl₂ + Cu, which means it is a dry cell battery, where the anode, zinc reacts with chloride that is the cathode. In the dry battery cell, the chemical energy is stored in it, which converts into electrical energy.
The voltage will be minimum, which is -1.1. The liquid battery cells or the electric fittings in our house contain high voltages because it gets direct current, but dry battery cells contain minimum amount of voltage and it is used to operate small objects.
Thus, the standard voltage will be -1.1 Vol.
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Al(s) + NaOH(aq) → Al(OH)3(s) + Na+(aq) displacement, or decomposition.
Answer:
Displacement
Explanation:
OH- in the reactant side of the reaction has switched from Na+ to Al 3+ in the product side. Decomposition is where a compound from the reactant side of the reaction would dissolve into elements in the product side, but that's not the case in this example.
If the PH is 5.85.how do I calculate for an acid ?[H^+]
Answer:
if its under 7 then it's an acid you neek over 7 is alkaline
What is the identity of the element? Help please
Answer:
10
Explanation:
The identity of an element refers to the specific element that is being referred to. The identity of the element is phosphorus (P).
To determine the identity of the element based on the given idealized PES (Photoelectron Spectroscopy) spectrum, we need to examine the pattern of relative number of electrons vs. energy levels.
The PES spectrum shows the relative number of electrons at different energy levels, and it is usually plotted with the relative number of electrons on the y-axis and the energy levels on the x-axis.
From the given data, we can see that there are three peaks with the following approximate values:
Energy (MJ/mol): ~1000, Relative number of electrons: ~1000
Energy (MJ/mol): ~100, Relative number of electrons: ~100
Energy (MJ/mol): ~10, Relative number of electrons: ~10
Based on this information, we can infer that the element has three distinct electron energy levels or subshells with approximately 1000, 100, and 10 electrons each.
To identify the element, we need to consider the electron configuration of elements in the periodic table and find an element that has three energy levels or subshells with roughly the same number of electrons.
The element that matches this pattern is phosphorus (P), which has the electron configuration: 1s² 2s² 2p⁶ 3s² 3p³. This configuration has 2 electrons in the 1st energy level (1s²), 8 electrons in the 2nd energy level (2s² 2p⁶), and 5 electrons in the 3rd energy level (3s² 3p³). The numbers are not exact matches, but they are relatively close to the given values in the PES spectrum.
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In the adjoining figure, the circles with the + sign represent protons and the empty circles represent neutrons. Determine which atoms in the figure are isotopes of each other.
Answer:
2 and 3 explanation in the comments
Write a balanced equation for the ionization of hydrochloric acid in water. Assume that hydronium ion is formed. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.)
Answer:
HCl(g) + H₂O(l) -> Cl⁻(aq) + H₃O⁺(aq)
Explanation:
Usually when we have HCl in a lab, it's already dissolved in water. It's just HCl(aq). If we want to look at adding pure HCl, that'll be a gas. We should note that HCl is a strong acid that will break apart completely. One might not say that this is a chemical reaction so much as a dissociation. Strong acids are proton donors and form hydronium cations in aqueous solution.
The balanced equation for the ionization of hydrochloric acid (HCl) in water, forming hydronium ions (H₃O⁺) and chloride ions (Cl⁻) is:
HCl(aq) + H₂O(l) → H₃O+(aq) + Cl⁻(aq). The symbol for hydrochloric acid is HCl. H₂O stands for water. The hydronium ion, or H₃O+, is created when the acid HCl gives a proton (H+) to a water molecule.
The chloride ion, which is what's left of the HCl molecule after it's been ionized, is denoted by the symbol Cl-.
The reaction can move both in the forward (ionization) and backward (recombination) directions, according to the double arrow ().
Thus, The balanced equation for the ionization of hydrochloric acid (HCl) in water, forming hydronium ions (H₃O⁺) and chloride ions (Cl⁻).
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