Chemistry Test Chemical Equilibrium 2

Question 1

The reaction quotient Q is used primarily to:

Accepted Answer

Predict the direction a reaction will shift to reach equilibrium

Answer

Comparing Q to Kc tells you whether the system needs to shift toward products (Q < Kc), toward reactants (Q > Kc), or is already at equilibrium (Q = Kc).

Question 2

If Q > Kc for a reaction, which direction will the reaction shift to reach equilibrium?

Accepted Answer

To the left, producing more reactants

Answer

When Q > Kc, there are too many products relative to equilibrium, so the reaction shifts left (reverse direction) to reduce product concentrations.

Question 3

According to Le Chatelier's Principle, increasing the pressure on the equilibrium N₂(g) + 3H₂(g) ⇌ 2NH₃(g) will:

Accepted Answer

Shift equilibrium to the right toward NH₃

Answer

Increasing pressure favors the side with fewer moles of gas; the left has 4 moles (1+3) and the right has 2 moles, so equilibrium shifts right toward NH₃.

Question 4

For the exothermic reaction: N₂(g) + 3H₂(g) ⇌ 2NH₃(g) + heat, increasing the temperature will:

Accepted Answer

Decrease Kc and shift equilibrium toward reactants

Answer

For an exothermic reaction, heat is a product; adding heat (increasing temperature) shifts the equilibrium left toward reactants, decreasing Kc.

Question 5

Adding an inert (noble) gas at constant volume to a gaseous equilibrium system will:

Accepted Answer

Not affect the equilibrium position

Answer

At constant volume, adding an inert gas increases total pressure but does not change the partial pressures or concentrations of the reactants or products, so equilibrium is unaffected.

Chemistry Practice Test Practice Test

Chemistry Practice Test Practice Test

Chemistry Test Chemical Equilibrium 2