AP Chemistry Unit 7 Equilibrium

For the reaction pictured how many moles of nitrogen gas (N2) are required to produce 18 mol of ammonia (NH3)?

• 18

• 9.0

• 4.5

• 36

Tags

NGSS.HS-PS1-7

If a chemical reaction involving substance A and B stops when substance B is completely used up, then substance B is referred to as the

• excess reactant.

• limiting reactant.

• primary reactant.

• primary product.

In most chemical reactions the amount of product obtained is

• more than the theoretical yield.

• equal to the theoretical yield.

• more than the percent yield.

• less than the theoretical yield.

Tags

NGSS.HS-PS1-6

The coefficients in a chemical equation represent which type of ratio?

• mass to mass ratio

• mole to mole ratio

• mass to mole ratio

• mole to mass ratio

Tags

NGSS.HS-PS1-7

Which is true of the reaction shown below?

• Two molecules of Substance Y will be left over when this reaction goes to completion.

• Substance Y is the limiting reagent in this reaction.

• The addition of more molecules of Substance X will not affect the amount of Substance Z that can be made.

• The mole ratio of this reaction is 6:5:6.

Tags

NGSS.HS-PS1-7

• 2 : 3

• 1 : 2

• 1 : 1

• 1 : 3

Tags

NGSS.HS-PS1-7

When a catalyst is added to a reaction, a decrease occurs in the

• activation energy

• heat of reaction

• potential energy of the reactants

• potential energy of the products

The change in free energy of a chemical equation is represented by a

• △H

• △G

• △T

• △S

The changes in ice to water involve

• and absorption of heat and an increase in entropy

• a release of heat and an increase in entropy

• a release of heat and a decrease in entropy

• an absorption of heat and a decrease in entropy

Tags

NGSS.HS-PS3-4

Based on the equation △G = △H - T△S, a chemical reaction will most likely occur spontaneously if

• △H is + and △S is +

• △H is - and △S is +

• △H is - and △S is -

• △H is + and △S is -