Question

For which of the following reactions at equilibrium at constant temperature doubling the volume will cause a shift to the right ?

• A. $N_2{O}_4\left(g\right)\rightleftharpoons 2N{O}_2\left(g\right)$
• B. $CaC{O}_3\left(s\right)\rightleftharpoons CaO\left)\right(s)+C{O}_2(g)$
• C. $2CO\left(g\right)+O_2\rightleftharpoons 2C{O}_2\left(g\right)$
• D. $N_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2NO\left(g\right)$

Answer 1

Answer: (A), (B)

The correct options are
A $N_2{O}_4\left(g\right)\rightleftharpoons 2N{O}_2\left(g\right)$
B $CaC{O}_3\left(s\right)\rightleftharpoons CaO\left)\right(s)+C{O}_2(g)$

When the volume is doubled, the pressure is reduced to half. In such case, the reaction with which the total number of moles of products is greater than the total number of moles of reactant, will shift the equilibrium towards right. This is true for the reactions in options A and B.