Question

Now let us do some Le Chatelier C(s)+H2O (g)←→CO (g) +H2 (g)AH-+131 kJ (in case you don't remember, this is an endothermic reaction). 4. A rigid container holds a mixture of graphite pellets (C(s)), water vapor, carbon monoxide gas, and hydrogen gas at equilibrium. State whether the number of moles of CO (g) in the container will increase, decrease, or remain the same after each of the following disturbances is applied to the original mixture. For each case, assume that all other variables remain constant except for the given disturbance. Explain each answer with a short statement. Stating the direction of shift is NOT an explanation. a. Additional hydrogen gas is added to the equilibrium mixture at constant volume. b. The temperature of the equilibrium mixture is increased at constant volume. c. The volume of the container is decreased at constant temperature. d. The graphite pellets are pulverized.

Answer 1

For letter a)

For all of the letters, we need to consider Le Chatelier's principle, which states that any changes made to to the equilibrium, will be opposed by such to get back to equilibrium.

In case hydrogen concentration increases, the equilibrium will try to displace the equilibrium to the reactants, so it will be displaced to the left and more reactants will be produced.

For letter b)

In this case, we have an endothermic reaction, so if the temperature is increased, the reaction will try to absorb that heat, hence, will produce more reactants so that equilibrium may be achieved.

For letter c)

As in this reaction we have the same amount of moles on both sides of the equation (2 and 2), reducing the volume (hence increasing the pressure) will have no effect.

For letter d)

Grinding the pellets only increases the rate of the reaction, it does not affect the equilibrium at all.