(a(i))[2]
Fig. 3.1 shows the reaction pathway diagram for the decomposition of sodium hydrogencarbonate. Identify the energy changes marked A and B.
(a(ii))[1]
Using the reaction pathway diagram, explain why the decomposition of sodium hydrogencarbonate is endothermic.
(b)[1]
Describe a chemical test for carbon dioxide and state the observation if carbon dioxide is present.
(c)[3]
A sample of sodium hydrogencarbonate is fully decomposed. A total volume of $230\text{ cm}^3$ of carbon dioxide, measured at r.t.p., is produced. Calculate the mass of the sample of sodium hydrogencarbonate. Give your answer to two significant figures.