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Answer:

IS IT MULTIPLE CHOICE

Explanation:

Answer:

Hydrogen and fuel cell technologies power cars, buildings and more. But how ... Test your knowledge with this quiz! ... How do fuel cells generate electricity

Answer:

A

Explanation:

fuel cell is a device that converts the chemical energy from fuel into electricity via a chemical reaction with oxygen or another oxidizing agent. Batteries work in a closed system, while fuel cells require their reactants to be replenished.

Answer:

Explanation:

When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released and photon is emitted.

this emitted photon is depicted as a small wave-packet being expelled by the atom in a well-defined direction.

Answer:

43.5

Explanation:

Hope that helps

Answer:

Compound A, C8H10, absorbed 3 equivalents of H2 on catalytic hydrogenation over a Pd/C catalyst to give B (C8H16). On ozonolysis, compound A gave, among other things, a ketone which was identified as cyclopentanone. On treatment with NaNH2 in NH3, followed by addition of iodomethane, compound A gave a new hydrocarbon, C (C9H12). Draw the structure of Compound A and Compound B.

Explanation:

The degree of unsaturation in the given compound A  C8H10 is:

DU= (Cn+1)-Hn/2 -Xn/2 +Nn/2

DU=(8+1)-10/2

    =9-5

    =4

So, the given compound has either three double bonds and a ring or four double bonds or four rings.

Given,

compound A C8H10 absorbed three equivalents of H2 on catalytic hydrogenation that means compound A has three double bonds or it has one double bond and one triple bond.

The structure of compounds A, B and C along with the entire reaction is shown below:

Answer:

0.375mL of solution of nalorphine must be injected

Explanation:

A solution of 0.40% (w/v) contains 0.40g of solute (In this case, nalorphine), in 100mL of solution. To obtain 1.5mg of nalorphine = 1.5x10⁻³g of nalorphine are needed:

1.5x10⁻³g * (100mL / 0.40g) =

Answer:

27 g/mol of E

Explanation:

Note that percentage by mass= mass of each element present. So, since there is 90% of E, there is 90g of E present. By implication, there are 10g of H corresponding to 10%H. Note that there is 100g of EH3

1 moles of E corresponds to 90 g of E

Mole ratio of E: H= 1:3

Thus

Number of moles of H = 10g/ 1g/ mol = 10 moles of H

Since E contains 1/3 the number of moles of H

Number of moles of E = 1/3 × 10 = 3.33 moles of E

Molar mass of E= mass of E/ number of moles of E

Since mass of E = 90 g

Molar mass of E = 90g/3.33 moles

Molar mass of E = 27 g/mol

Answer:

Yard . I hope this helped:))

Answer:

A) 1.3 × 10⁻⁵ mol/L

Explanation:

Step 1: Write the balanced equation for the solution of AgCl

AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)

Step 2: Make an ICE Chart

        AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)

I                           0             0

C                        +S            +S

E                          S              S

If we replace the solubility (S) in the Ksp expression, we get,

Ksp = [Ag⁺] [Cl⁻] = S × S = S²

S = √Ksp = √1.8 × 10⁻¹⁰ = 1.3 × 10⁻⁵ mol/L

Answer: The %v/v of the given KCl solution is 7.6%.

Explanation:

Given: Volume of solute = [tex]4.6 \times 10^{1} ml[/tex]

Volume of solution = [tex]6.0 \times 10^{-1} g/ml[/tex]

Formula used to calculate %v/v is as follows.

[tex]\frac{volume of solute}{volume of solution} \times 100[/tex]

Substitute the values into above formula as follows.

[tex]\frac{volume of solute}{volume of solution} \times 100\\\frac{4.6 \times 10^{1}}{6.0 \times 10^{-1}} \times 100\\= 7.6[/tex]

Thus. we can conclude that the %v/v of the given KCl solution is 7.6%.

Answer:

A 1 liter volumetric flask should be used.

Explanation:

First we convert 166.00 g of KI into moles, using its molar mass:

Molar mass of KI = Molar mass of K + Molar mass of I = 166 g/mol

Then we calculate the required volume, using the definition of molarity:

Liters = moles / molarity

When we pre-weigh a glass vial to hold our sample and find its mass to be 5.010 g. Then we add our sample to the vial and reweigh it on the same balance and find that the mass has increased to 6.130 g. The mass of the sample in grams is 1.12 g.

Avogadro's number is the number of units in one mole of any substance and equals to 6.02214076 × 10²³. The units can be electrons, atoms, ions, or molecules.

No. of moles is defined as a particular no. of particles that we can calculate with the help of Avogadro’s number.

Mass of a particular product is also find out by stoichiometry of a reaction as per the no. of mole given in the reaction.

Mass is generally can be represented by units like Kg, g etc.

Given,

weigh of glass vial = 5.010 g

weigh of glass vial with sample = 6.130 g

Therefore, When we pre-weigh a glass vial to hold our sample and find its mass to be 5.010 g. Then we add our sample to the vial and reweigh it on the same balance and find that the mass has increased to 6.130 g. The mass of the sample in grams is 1.12 g.

Learn more about mass, here:

https://brainly.com/question/19694949

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Actual yield over theoretical yield, then multiply by 100

Answer:

Mixture of a Strong Acid and a Strong Base

On mixing a strong acid and strong base neutralization (pH = 7) takes place. The resulting solution may be an acid or base depending on the Concentration. Say, N1, V1 is the strength and volume of the strong acid and N2, V2 is the strength and volume of the strong base

Explanation:

Most introductory chemistry books will teach that the reaction between an acid and a base is called neutralization, and the products formed are water and a salt

Answer:

physical change because the gaseous water is chemically the same as the liquid

Explanation:

Matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.

Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.

A physical change can be defined as a type of change that only affects the physical form of a chemical substance (matter) without having any effect on its chemical properties. Thus, a physical change would only affect the physical appearance and properties of a chemical substance (matter) but not its chemical properties.

This ultimately implies that, a physical change result in a change of matter from one form or phase (liquid, solid or gas) to another without a corresponding change in chemical composition.

Hence, the boiling of water is considered to be a physical change because the gaseous water is chemically the same as the liquid i.e there isn't any changes in chemical composition of water when boiling.

Answer:

c. Kc and Kp are equal when the sum of the stoichiometric coefficients for the products equals the sum of the stoichiometric coefficients for the reactants.

Explanation:

Hello there!

In this case, according to the given information, it turns out firstly necessary for us to write the relationship between Kc and Kp in terms of the temperature and the change in the stoichiometric coefficients:

[tex]Kp=Kc(RT)^{\Delta \nu}[/tex]

Thus, we can see that the Kp=Kc just when Δυ=0, which is the sum of the coefficients of products minus that of reactants; and therefore, the correct answer will be c. Kc and Kp are equal when the sum of the stoichiometric coefficients for the products equals the sum of the stoichiometric coefficients for the reactants.

Regards!

Answer:it dissolves and evaporates

Explanation:

The question is incomplete, the complete question is:

A 7.00 L tank at [tex]21.4^oC[/tex] is filled with 5.43 g of sulfur hexafluoride gas and 14.2 g of sulfur tetrafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction and partial pressure of each gas. Round each of your answers to significant digits.

Answer: The mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.  The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of sulfur hexafluoride = 5.43 g

Molar mass of sulfur hexafluoride = 146.06 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of sulfur hexafluoride}=\frac{5.43g}{146.06g/mol}=0.0372mol[/tex]

Given mass of sulfur tetrafluoride = 14.2 g

Molar mass of sulfur tetrafluoride = 108.07 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of sulfur tetrafluoride }=\frac{14.2g}{108.07g/mol}=0.1314mol[/tex]

Total moles of gas in the tank = [0.0372+ 0.1314] mol = 0.1686 mol

Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:

[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)

where n is the number of moles

Putting values in equation 2, we get:

[tex]\chi_{SF_6}=\frac{0.0372}{0.1686}=0.221[/tex]

[tex]\chi_{SF_4}=\frac{0.1314}{0.1686}=0.779[/tex]

Hence, the mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779

Answer:

No reaction occurs.

Explanation:

The molecular reaction is as follows;

MgSO4(aq) + Ni(NO3)2(aq) ----> Mg(NO3)2(aq) + NiSO4(aq)

We can see from the reaction above that the both products of the reaction are soluble. Recall that a double replacement reaction often yields one insoluble product which separates as a precipitate.

This reaction does not occur since the two products that ought to be obtained are soluble in water.

Answer:

It is always less than the theoretical yield.

Explanation:

74.92 g.

(The mass of one mole of arsenic is 74.92 g.

Answer:

0.414 mole (3 sig. figs.)

Explanation:

Given grams, moles = mass/formula weight

moles in 18.2g CO₂(g) = 18.2g/44g/mole = 0.413636364 mole (calc. ans.)

≅ 0.414 mole (3 sig. figs.)

Answer: The correct option is B) oxidized

Explanation:

Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously.

The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.

A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.

For the given chemical reaction:

[tex]Zn+H_2SO_4+S\rightarrow ZnSO_4+H_2[/tex]

On the reactant side:

Oxidation number of H = +1

Oxidation number of Zn = 0

Oxidation number of S = +6

Oxidation number of O = -2

On the product side:

Oxidation number of H = 0

Oxidation number of Zn = +2

Oxidation number of S = +6

Oxidation number of O = -2

As the oxidation number of Zn is increasing from 0 to +2. Thus, it is getting oxidized. Similarly, the oxidation number of H is decreasing from +1 to 0. Thus, it is getting reduced.

Hence, the correct option is B) oxidized

Answer: Pressure of the gas is 0.129375 atm when the volume of the vessel increased by a factor of 16.00.

Explanation:

The formula for ideal gas equation is as follows.

[tex]PV = Nk_{b}T[/tex]

where,

[tex]k_{b}[/tex] = Boltzmann constant

N = number of moles

That can also be written as:

[tex]\frac{PV}{T} = constant[/tex]

As pressure and volume are inversely proportional to each other. So, if one of the state variable is increased then the other one will decrease or vice-versa.

So, if volume of the vessel increased by a factor of 16.00 then it means pressure is decreased by a factor of 16.00

Therefore, final volume is as follows.

[tex]65.8 L \times 16.00\\= 1052.8 L[/tex]

Now, final pressure is as follows.

[tex]\frac{2.07}{16.00}\\= 0.129375 atm[/tex]

Initially the product of pressure and volume is as follows.

[tex]PV = 2.07 \times 65.8\\= 136.206[/tex]

Hence, if volume of the vessel increased by a factor of 16.00 and pressure is decreased by a factor of 16.00 then its product is as follows.

[tex]PV = 0.129375 \times 1052.8\\= 136.206[/tex]

Here, product of pressure and volume remains the same.

Thus, we can conclude that pressure of the gas is 0.129375 atm when the volume of the vessel increased by a factor of 16.00.

Answer:

c it does not change the energy state

Explanation:

Answer:

2.11×10²³ atoms.

Explanation:

From the question given above, the following data were obtained:

Mass of Ne = 7 g

Number of atoms =?

Recall:

1 mole of Ne = 6.02×10²³ atoms

1 mole of Ne = 20 g

Thus,

20 g of Ne = 6.02×10²³ atoms

Finally, we shall determine the number of atoms in 7 g of Ne. This can be obtained as follow:

20 g of Ne = 6.02×10²³ atoms

Therefore,

7 g of Ne = (7 × 6.02×10²³) / 20

7 g of Ne = 2.11×10²³ atoms

Thus, 7 g of Ne contains 2.11×10²³ atoms.

Answer:

climate change

Explanation:

climate change is driving force of evolution because when the climate is changed the animal and human need to adapt to it's natural change.

Answer:

Storage solution; deionized water; stabilizes.

Explanation:

The pH scale measures the concentration of hydrogen ions in acidic and alkaline solutions.

In chemistry, it literally means power of hydrogen ions and it is a measure of the molar concentration of hydrogen ions in a particular solution, thus specifying the acidity, neutrality or basicity of chemical solutions.

Mathematically, the pH of a solution is given by;

[tex] pH = -log_{10}(H^{+}) [/tex]

Hence, a solution with a pH of 7 is neutral. Also, a solution with a pH below 7 is acidic but basic (alkaline) if it's pH is above 7.

A pH meter can be defined as a scientific instrument or device designed and developed for the measurement of the hydrogen-ion concentration in water-based solutions, in order to determine their level of acidity or alkanility.

When using a pH meter to take a measurement, you should keep it in a storage solution until it is needed. Also, a deionized water should be used to rinse the pH meter and gently pat dry.

Furthermore, the pH meter should be placed in a given sample solution and a reading of the measurement taken when the pH of the solution stabilizes.

Answer:

c

Explanation:

it is because the chemical reaction will have the exposure to all the minerals with Microsoft word