Question

On adding co2 to e1. Decomposition of caco3 eq2 co2 gives co and 1/2o2.

• A. pressure of CO2 increases
• B. pressure of CO2 decreases
• C. no shift in second eq.
• D. backward shift in 1st eq.

Answer 1

Answer: (A), (D)

1. pressure of CO2 increases, 4) backward shift in 1st eq.

Answer 2

Adding $CO_2$ gas to the system increases its partial pressure. For the first equilibrium, $CaCO_3(s) \rightleftharpoons CaO(s) + CO_2(g)$, the equilibrium constant $K_p = P_{CO_2}$. An increase in $P_{CO_2}$ shifts this equilibrium to the left (backward shift) to reduce $P_{CO_2}$. For the second equilibrium, $CO_2(g) \rightleftharpoons CO(g) + \frac{1}{2}O_2(g)$, $CO_2$ is a reactant. An increase in $P_{CO_2}$ shifts this equilibrium to the right, consuming $CO_2$. Thus, the pressure of $CO_2$ increases, and the first equilibrium shifts backward.