Lawrie Ryan and Roger Norris Solutions for Chapter: Equilibria, Exercise 4: Question

Bromine is a reddish-brown liquid that vaporises at room temperature. Some liquid bromine is put in a closed jar. The colour of the bromine vapour above the liquid gets darker and darker until the depth of colour remains constant. Bromine liquid still remains in the jar. Explain what is happening in terms of changes in concentration of the bromine molecules in the vapour.

Predict the effect of increasing the temperature on the reaction: ${\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)+\mathrm{CO}\left(\mathrm{g}\right); ∆\mathrm{H}=+41.2 \mathrm{kJ} {\mathrm{mol}}^{-1}$.

In the reaction ${\mathrm{Ag}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)\rightleftharpoons {\mathrm{Ag}}_2\mathrm{O}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$, increasing the temperature increases the amount of carbon dioxide formed at constant pressure. Is this reaction exothermic or endothermic? Explain your answer.