State the statement of Hess’ Law.
Construct a balanced equation for the reaction between potassium carbonate, $\text{K}_2\text{CO}_3$, and hydrochloric acid.
Calculate the heat released in experiment 1, and include your units. Use appropriate data from the Data Booklet and assume that all solutions have the same specific heat capacity as water.
Use your answer to (ii) to calculate the enthalpy change per mole of $\text{K}_2\text{CO}_3$. Give your answer in $\text{kJ mol}^{-1}$ and include a sign in your answer.
Explain why the hydrochloric acid has to be in excess.
Construct a balanced equation for the reaction carried out in experiment 2.
Calculate the amount of heat absorbed in experiment 2.
Use your answer to (ii) to calculate the enthalpy change per mole of $\text{KHCO}_3$. Give your answer in $\text{kJ mol}^{-1}$ and include a sign in your answer.
When $\text{KHCO}_3$ is heated, it breaks down into $\text{K}_2\text{CO}_3$, $\text{CO}_2$ and $\text{H}_2\text{O}$. $2\text{KHCO}_3 \rightarrow \text{K}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O}$. Use Hess’ Law together with your answers to (b)(iii) and (c)(iii) to work out the enthalpy change for this reaction. Give your answer in $\text{kJ mol}^{-1}$ and include a sign in your answer.