Answer:
A
Explanation:
Cells form tissues
Tissues form organs
Organs for organ systems
Organ systems form organism
Answer:
A the organism
Explanation:
Cause every answer is what is in a human form but the organism is what is made up of all of them
The mass of single iridium atom is 3.19*10^-22 grams how many iridium atoms would be in 56.4 milligrams of iridium
Oxygen gas O2 was placed into a closed container at 273.15K. What is the change in temperature that is required in order to increase the pressure from 2.50atm to 7.50atm and decrease the volume from 3.50L to 1.50L?
Answer: 351.19K
Explanation: This is a case were the combined gas equation can be applied.
Combined gas equation is given as; P1V1/T1 = P2V2/T2,
where P1 = Initial pressure = 2.50 atm
P2= Final pressure = 7.50 atm
V1 = Initial volume = 3.50L
V2 = Final Volume = 1.50L
T1 = Initial Temperature = 273.15K
T2 = Final Temperature = ?
∴ 2.50atm x 3.50L / 273.15K = 7.50atm x 1.50L / T2
Making T2 the subject of Formular; we then have;
T2 = P2 V2 T1 / P1 V1 = 7.50atm x 1.50L x 273.15K / 2.50atm x 3.50L
= 3072.94 / 8.75 = 351.19K
The change in temperature (T2) is 351.19K.
what numbers go in the blank _Na2Co3+_HCI > _NaCl+H2O+_CO2
Answer: [tex]Na_2CO_3+2HCl\rightarrow 2NaCl+H_2O+CO_2[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation will be:
[tex]1Na_2CO_3+2HCl\rightarrow 2NaCl+H_2O+1CO_2[/tex]
Thus the numbers that go in the blanks are 1, 2, 2, and 1 respectively for [tex]Na_2CO_3[/tex], [tex]HCl[/tex] , [tex]NaCl[/tex] and [tex]CO_2[/tex] respectively.
How many grams is 4.2X10^24 atoms of sulfur?
The rate of the reaction is ?
The rate of a chemical reaction is defined as the change in the concentration of a reactant or a product over the change in time, and concentration is in moles per liter, or molar, and time is in seconds. So we express the rate of a chemical reaction in molar per second.
Answer:
Hey!
Your answer is The Rate of a Reaction is a measurement of how the speed at which a reactant is used up / or a product is formed.
Explanation:
R of R (Rate of Reaction) can be affected by:
Reactant concentration (how much of the substance is there to react)
The state of the reactants (whether they are in a solid/liquid/gas state)
The total surface area (more particles of the substance means more reactions...)
The Temperature (hot=quicker cool=slower)
The presence of a catalyst (catalysts speed up the Rate of the Reaction)
HOPE THIS HELPS!!
4. A taxi ride costs $5 plus .75 cents per mile. If I
ride for 120 miles, how much will be charged?
Answer:
$95
Explanation:
.75 x 120 = 90
90+5 = 95
Light brings many chemical changes. Can you think of any chemical change brought about by light?
Answer:
MRCORRECT has answered the question
Explanation:
Film photography is another example ofchemical reaction by light. In this example, the chemical compounds coated on the film go through a chemical reaction. ... These plates (usually made of aluminum) are coated with a photosensitive compound consisting of a polymer and a photosensitivechemical system.
The change in entropy, ΔS∘rxn , is related to the the change in the number of moles of gas molecules, Δngas . Determine the change in the moles of gas for each of the reactions and decide if the entropy increases, decreases, or has little or no change. A. 2H2(g)+O2(g) ⟶ 2H2O(l) Δngas= mol The entropy, ΔS∘rxn , increases. decreases. has little or no change.
Explanation:
Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter
PLEASE help! BRAINLIEST to correct answer!
Answer:
C
Explanation:
Answer:
I think its q
Explanation:
h is the Planck constant, c the speed of light
18.35 mL of an HCN solution were titrated with 35.4mL of a 0.268M NaOH solution to reach the equivalence point. What is the molarity of the HCN solution
Answer:
0.517
Explanation:
HCN + NaOH → NaCN + H2O [balanced as written]
(35.4 mL) x (0.268 M NaOH) x (1 mol HCN / 1 mol NaOH) / (18.35 mL HCN) = 0.517 M HCN
Answer: 0.517
Explanation:
Which of the following statements about an S N1 reaction mechanism is true? The reaction involves two steps and occurs fastest with tertiary alkyl halides. The reaction involves one step and occurs fastest with tertiary alkyl halides. The reaction involves one step and occurs fastest with primary alkyl halides. The reaction involves two steps and occurs fastest with primary alkyl halides.
Answer:
The reaction involves two steps and occurs fastest with tertiary alkyl halides
Explanation:
To solve such this we must know the concept of nucleophilic substitution reaction. The reaction involves two steps and occurs fastest with tertiary alkyl halides. Therefore, the correct option is option A.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The characteristics of SN1 mechanism:
SN1 reaction is a nucleophilic substitution reaction.
Leaving group, a nucleophile, electrophile and a solvent are present
Two types of enantiomers can be formed in the reaction depending on the preference of the nucleophile.
The first step is the slowest because a bond is being broken.
SN1 reaction involves two steps and occurs fastest with tertiary alkyl halides
Therefore, the correct option is option A.
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Which characteristic of a substance is considered a chemical property
Answer:
c
Explanation:
A chemist must prepare of nitric acid solution with a pH of at . He will do this in three steps: Fill a volumetric flask about halfway with distilled water. Measure out a small volume of concentrated () stock nitric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated nitric acid that the chemist must measure out in the second step. Round your answer to significant digits.
Answer:
The volume of concentrated nitric acid is
4.3mL
Explanation
Check the attachment
Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolate and measure the amount of gas produced. Wala Suppose the H, gas evolved by a certain chemical reaction taking place at 40.0 °C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 80.0 mL. Sketch of a gas-collection apparatus Calculate the mass of H, that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about the reaction conditions and the nature of the gases. XS?
Answer:
see explaination
Explanation:
Case 1) When we consider vapor pressure of H2O;
Let the pressure is 1 atm OR 760 torr.
As H2 is collected over water, we have to consider the vapor pressure of H2O as well.
Using data i.e. vapor pressure of H2O at 40° C = 55.365 torr
So, pressure of H2 = P = 760 - 55.365 = 704.635 torr = 704.635/760 = 0.9272 atm
Volume of H2 = 80 ml = 0.08 liter
Temperature (T) = 40 + 273 = 313 K
Gas constant (R) = 0.0821 L atm/mol K
Let n is moles of H2. Applying ideal gas equation;
PV = nRT
n = PV/RT = 0.9272 * 0.08 / 0.0821 * 313
n = 0.00289 moles
Mass of H2 = moles * molar mass = 0.00289 * 2.016 = 0.00582 grams
OR 5.8*10^-3 grams ...Answer
----> Case 2) When we don't consider vapor pressure;
Pressure of H2 = 1 atm, all other parameters will remain same as in case 1.
So, mass of H2 = 6.3*10^-3 grams
But Case 1) is correct approach as in question it is mentioned that H2 is collected over water.
A. An element with the valence electron configuration 5s1 would form a monatomic ion with a charge of ________. In order to form this ion, the element will _______ electron(s) from/into the _______ subshell(s).
B. An element with the valence electron configuration 2s22p4 would form a monatomic ion with a charge of ______. In order to form this ion, the element will ______ electron(s) from/into the _______ subshell(s)
Answer:
A) An element with the valence electron configuration 5s¹ would form a monatomic ion with a charge of +1. In order to form this ion, the element will lose electron(s) from/into the 5s subshell(s).
B) An element with the valence electron configuration 2s²2p⁴ would form a monatomic ion with a charge of +1. In order to form this ion, the element will lose electron(s) from/into the 2p (2pₓ specifically) subshell(s).
Explanation:
The secret to this task is to follow those rules for the stability of electronic structures of elements. The rules include
- Electrons are filled firstly into shells or subshells of lower energies first.
- While filling electronic structure or writing electronic structures for elements/ions, electrons are fed singly to the suborbital before pairing occurs, this is because the totally paired up electrons of a suborbital are more stable than the totally unpaired electrons of the same suborbital which is now in turn more stable than the combination of paired and unpaired electrons in the suborbitals.
A) For an element with its valence electron on 5s¹, this means that there is one valence electron on this atom's outermost shell and outermost suborbitals. So, to form a monoatomic ion, it would take between losing and gaining an electron. Gaining an electron leads to a 5s², which indicates empty 5p orbitals too and is therefore less stable than losing an electron which would lead to the loss of the shell 5 and focus on a completely filled 4-shell.
So, losing the electron from the 5s suborbital to become a monotonic ion makes it acquire a charge of +1.
B) Just like the explanation in (A), to form a monoatomic ion would require a loss or gain of an electron. With valence electrons 2s²2p⁴, gaining an electron would have led to a 2s²2p⁵ and a further breakdown as 2s²2pₓ²2pᵧ²2pz¹ which has unpaired and paired electrons in the 2p suborbital. This is evidently less stable than if an electron was lost, the valence electrons are 2s²2p³ and they are positioned in a totally unpaired fashion in the 2p suborbital as 2s²2pₓ¹2pᵧ¹2pz¹.
Hence, the more stable alternative is more likely to occur and the electron is lost from the 2pₓ suborbital to make the monoatomic ion of the element acquire a +1 charge status too because of lost electron too.
Hope this Helps!!!
The octet rule states that the atoms of the elements bond to each other in an attempt to complete their valence shell with eight electrons. In other words, the atoms will tend to give up or share electrons to complete eight electrons in the valence shell through an ionic, covalent or metallic bond.
In other words, the goal is to have the closest noble gas electron configuration, thus having the last complete electron shell and acquiring stability.
So, in this case, to comply with the octet rule:
A. An element with the valence electron configuration 5s¹ would form a monatomic ion with a charge of +1. In order to form this ion, the element will lose one electron from the 5s subshell.
For an element with its valence electron at 5s¹, this means that there is one valence electron in the outermost shell of this atom and in the outermost suborbitals. To form a monatomic ion, it would be necessary between losing or gaining an electron and that ion is stable. It takes less energy to lose the electron of the suborbital 5s and acquire a charge of of +1, than to acquire an electron, because it forms the 5s² suborbital, which indicates empty 5p orbitals too and is therefore less stable.
Also, in this way, the octet rule is fulfilled.
B. An element with the valence electron configuration 2s²2p⁴ would form a monatomic ion with a charge of -2. In order to form this ion, the element will gain two electron into the 2p subshell(s).
After gain two electron the atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas (2s²2p⁶). In this way, the octet rule is fulfilled and the ion is stable.
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If you collect 1.75 L of hydrogen gas during a lab experiment, when the room temperature is 23ºC and the barometric pressure is 105 kPa, how many moles of hydrogen will you have?
Answer:
[tex]n=0.0747mol[/tex]
Explanation:
Hello,
In this case, since we can consider hydrogen gas as an ideal gas, we check the volume-pressure-temperature-mole relationship by using the ideal gas equation:
[tex]PV=nRT[/tex]
Whereas we are asked to compute the moles given the temperature in Kelvins, thr pressure in atm and volume in L as shown below:
[tex]n=\frac{105kPa*\frac{0.009869atm}{1kPa}*1.75L}{0.082\frac{atm*L}{mol*K}*(23+273.15)K} \\\\n=0.0747mol[/tex]
Best regards.
Two identical light bulbs are connected to a battery in a series circuit.
An ammeter is wired into the circuit at measures a current of the
battery to be 0.5 Amps. The two light bulbs are then wired in parallel.
The ammeter shows that the current:
Answer:
0.10 amps
Explanation:
Argon-40 undergoes positron emission as shown:
48 Ar X+ IB
Enter the appropriate values for A and Z and the chemical
symbol for X
Answer:
[tex]\frac{40}{18}Ar => \frac{40}{17}Cl + \frac{0}{1}e\\[/tex]
Explanation:
The process of positron emission is better understood by the following reaction:
[tex]\frac{40}{18} Ar[/tex] → + [tex]\frac{40}{17} Cl + \frac{0}{1} e[/tex]. What is Positron emission?Positron emission may be defined as a subordinate type of radioactive decay called which is effectively known as beta decay. Due to this emission, a proton that is present inside a radionuclide nucleus significantly transformed into a neutron while liberating a positron and an electron neutrino.
According to the context of this question, Argon-40 undergoes the process of beta decay. Through which X element is formed which is known as chlorine. The atomic number (Z) of chlorine is 17, while the atomic mass (A) is 40 which is as identical to argon.
Therefore, the appropriate values for A and Z and the chemical symbol for X are 40 and 17 respectively.
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What is the mass defect of a mole of nuclei with 1.8 x 10^15 J/mol binding
energy?
Answer:
2.0 x 10^-2 kg/mol
Explanation:
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
*Text me at 561-400-5105 for private tutoring if interested: I can do homework, labs, and other assignments :)
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
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An empty weighing dish has a mass of 1.0041 ± 0.0002 g. After you add dried sodium chloride to the dish, the mass is 3.2933 ± 0.0002 g. You quantitatively transfer the sodium chloride into a 500.00 ± 0.05 mL volumetric flask and dilute to the mark with deionized water. The molar mass of sodium chloride is 58.440 g/mol. What is the absolute error in the concentration of the resulting solution? Report your answer normally to the correct number of significant figures with the correct unit.
Answer:
The correct answer to the following question will be "0.0013%".
Explanation:
The given values are:
Weight of an empty dish = 1.0041 ± 0.0002 g
Weight of dish + sodium chloride (NaCl) = 3.2933 ± 0.0002 g
Weight of NaCl = 2.2892 ± 0.0002 g
Now,
Volume of the solution = 500.00 ± 0.05 ± 0.0002
= 500.00 ± 0.0502 ml
So,
Molarity = [tex]\frac{W \ NaCl}{M \ NaCl} \times \frac{1000}{Volumes \ of \ solution}[/tex]
On putting the values in the above formula, we get
= [tex]\frac{(2.2892\addeq +0.0002)}{58.440}\times \frac{1050}{(500.00+0.0502)}[/tex]
= ([tex]3.917[/tex] ± [tex]0.0002[/tex]) × ([tex]2[/tex] ± [tex]0.0502[/tex])
= ([tex]0.7834[/tex] ± [tex].00001004[/tex])
Now,
Absolute error = [tex]\frac{0.00001004}{0.7834}\times 100[/tex]
= [tex]0.0013[/tex]%
What is the correct IUPAC name for Ag₂S?
Answer:
Acanthite. MFCD00003406
Explanation:
Which of the following 0.5 M aqueous salt solutions will have a pH of 7.0 at
LiF RbBr NaClO4 NH4Cl
A) LiF only B) NaClO4 only C) LiF and RbBr D) RbBr and NaClO4
Answer:
LiF and RbBr
Explanation:
Salt is an ionic compound that is made from the reaction of an acid and a base solution. Salts dissolve in water to give solutions that are acidic, basic, or neutral.
Salt formed from a strong acid and a weak base will make an acidic solution when added to water. The reason this occurs is because when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form hydronium ion.
If a salt is formed from a weak acid and a strong base, it dissolves in water and the conjugate base of the weak acid will accept a proton from water and yield the hydroxide ion. Hence the solution of the salt will be basic.
If the salt is formed from a strong acid and a strong base, the salt is neutral when dissolved in water. Both LiF and RbBr are formed from strong acids and strong bases hence they will have a pH of 7.0 in solution.
LiF RbBr NaClO4 NH4Cl is = LiF and RbBr The correction is 'C'.
What are the Salt solutions?
Salt is an ionic mixture that is made from the reaction of an acid and a base resolution. Salts liquefy in water to give solutions that are acidic, basic, or neutral.
Salt constructed from a strong acid and a breakable base will make an acidic solution when added to water. The reason this occurs is that when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form a hydronium ion.
If a grain of salt is formed from a weak acid and a powerful ground, it liquefies in water and the conjugate bottom of the weak acid will accept a proton from water and yield the hydroxide ion. Therefore, the solution of the salt will be basic.
If the salt is formed from a strong acid and a strong bottom, the salt is neutral when liquefied in water. Both LiF and also RbBr are formed from strong acids and powerful bases hence they will have a pH of 7.0 in resolution.
Therefore, the Correct option is 'C'
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Pure water at 25°C ionizes as what?
Answer:
see explanation
Explanation:
Pure water (H₂O) at 25°C follows an autoionization mechanism. That is, water reacts with itself to yield Hydronium Ions (H₃O⁺) and Hydroxide Ions (OH⁻) according to the following proton transfer mechanism.
2H₂O(l) ⇄ H₃O⁺(aq) + OH⁻(aq) => H₂O(I) ⇄ H⁺(aq) + OH⁻(aq) as a shorthand form of the process primarily for convenience. The H⁺ ion is a proton and would not be found in solution as an independent free form particle, but the shorthand format is generally accepted in the chemical community because of it's ease of application.
Other related facts of water ionization include...
At 25°C/1atm => the molar concentrations of [H⁺(aq)] = 1 x 10⁻⁷M and [OH⁻(aq)] = 1 x 10⁻⁷M
Applying to the equilibrium ionization expression for water ...
H₂O(I) ⇄ H⁺(aq) + OH⁻(aq)
C(eq): ∞* 1 x 10⁻⁷M 1 x 10⁻⁷M
*The molar concentration of water is considered to be infinite [∞] as compared to concentration values of H⁺(aq) and OH⁻(aq) and is for practical purposes assumed to be constant. This leads to the classic Ionization Product constant expression for water (Kw = [H⁺(aq)][OH⁻(aq)].
The value for Kw at 25°C/1atm is then ...
Kw = [H⁺(aq)][OH⁻(aq)] = (1 x 10⁻⁷M)(1 x 10⁻⁷M) = 1 x 10⁻¹⁴M² (units are typically dropped and Kw listed simply as 1 x 10⁻¹⁴.
With this, the terms acidity, neutral and alkaline acid base systems are defined and related to pH. That is, if ...
[H⁺(aq)] > [OH⁻(aq)] => Acidic System => pH < 7
[H⁺(aq)] = [OH⁻(aq)] => Neutral System => pH = 7
[H⁺(aq)] < [OH⁻(aq)] => Alkaline System => pH < 7
pH = -log[H⁺] and pOH = -log[OH⁻] and pH + pOH = 14.
Is it true or false?
Answer:
True
Explanation:
Burning waste can lead to air pollution and release of greenhouse gases. Carbon dioxide is one of those gases.
The largest contributed to water pollution is
Answer:
this si from google hope it helps
Explanation:
The Main Causes of Water Pollution in the U.S.
Runoff from Agricultural Operations. Agriculture represents one of the biggest sources of water pollution in the country. ...
Runoff and Nonpoint Source Pollution. ...
Industrial Activities. ...
Leakage from Underground Storage and Piping. ...
Leaking Sewers. ...
Vehicle Emissions. ...
Landfill Leakage. ...
Hazardous Waste.
Answer:
Runoff and Non-point Source Pollution.
Explanation:
it's caused by rainfall or snow-melt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground and NPS is it's abbreviation.
What are 3 stages of the water cycle are
Which of the following describes the change in atomic mass and atomic number during this reaction?
5) Low iron concentration (as low as 0.02 nM) in the open ocean limits phytoplankton growth. Preconcentration is required to determine such low concentrations. Trace Fe3 from a large volume of seawater is concentrated onto a 1.2 mL chelating resin column, the column is then rinsed with 30 mL of high purity water and eluted with 10 mL of 1.5 M high purity HNO3. a.) For each sample, seawater is passed through the column of 17 h at 10 mL./min. How much is the concentration of Fe3 in the 10 mL of HNO3 eluate increased by this preconcentration procedure
Answer:
Check the explanation
Explanation:
Sample volume V= 10 mL/min x 17 h x 60 min/h / 1000 mL/L = 10.2 L
The concentration is increased
10200 mL (sample volum) / 10 mL (eluted sample) = 1020 times.
57x10-9 M / 1020 = 5.6x10-12 M
1.5 M HNO3 will contain ≤ 2ppm x (1.5M/15.7M ) ≤ 0.190 ppm ≤ 190 ppb
Ignoring this is reagent impurity and calculating for sea water
≤ 190 ppb /1020 = 0.186 ppb = 0.186 x 10-9g/mL = 0.186 x 10-6g/L =
0.186 x 10-6g/L / 56 g/mol = 0.003 x10-6 M = 3 nM
