Unit 7 Equilibrium AP Chemistry

If the pressure of a system is increased, which direction will equilibrium shift?

• toward the side with less moles of gas

• toward the side with more moles of gas

• it will not shift

At what time does the system first reach equilibrium?

• 24s

• 40s

• 60s

• 80s

Tags

NGSS.HS-PS1-5

If a K value is greater than 1,

• more products are present at equilibrium

• more reactants are present at equilibrium

Tags

NGSS.HS-PS1-6

When calculating ΔH from chemical equations with known enthalpies, if you double reaction coefficients, what happens to the overall ΔH value?

• it doubles

• it is squared

• the sign changes

• nothing

For any reaction at chemical equilibrium, the concentrations of products and reactants

• are equal.

• change

• remain unchanged

• decrease

What are the two factors to look for when determining if the reaction is at equilibrium?

• Forward reaction rate is faster than the reverse and concentrations are equal

• Forward and reverse reaction rates are equal and concentration is constant

• Forward and revers reaction rates are equal and concentration is equal

• Forward reaction rate is faster than the reverse and concentration is equal

Tags

NGSS.HS-PS1-6

Which of the following statements correctly describes any chemical reaction that has reached equilibrium?

• The reaction is now irreversible.

• The rates of the forward and reverse reactions are equal.

• Both forward and reverse reactions have halted.

• The concentrations of products and reactants are equal.

Tags

NGSS.HS-PS1-6

TRUE or FALSE:

"At equilibrium, the CONCENTRATIONS of products STAY the SAME"

• True

• False

Tags

NGSS.HS-PS1-6

Calculate Kc for the reaction HI_(g) —> H_2(g) + I_2(g) given that the concentrations of each species at equilibrium are as follows: [HI] = 0.85 mol/L, [I₂] = 0.60 mol/L, [H₂] = 0.27mol/L.

• 0.19

• 0.22

• 4.5

• 5.25

• 160

Why is equilibrium called a dynamic state?

• Chemists try to convert as much reactants as possible into products.

• The reactions at equilibrium continue to take place once equilibrium is established.

• The products of a forward reaction are favored, so equilibrium lies to the right.

• All chemical reactions are considered to be reversible under suitable conditions.