CSEC Chemistry · January 2015 · Paper 2 · Question 1(a)(ii)

The solubility of solid X in water at various temperatures is determined through a series of experiments (1-5). The procedure involves adding 2g of X to varying volumes of water, heating until dissolved, then cooling and noting the temperature at which crystals of X first reappear. Some data is in Table 1, and reappearance temperatures for experiments 2-5 are shown in Figure 1.

determining and recording the corresponding values for the solubility of X. [At each temperature, Solubility of X = (mass of X / mass of water) × 100; assume 1 cm³ water = 1 g.]

This question uses a figure or table from the paper — you'll see it when you practise.