Solubility curves
3 marks · EasyThe table below shows the solubility of calcium nitrate at various temperatures.
| Temperature /°C | Solubility /g per 100 g water |
|---|---|
| 10 | 129 |
| 30 | 136 |
| 50 | 145 |
| 70 | 151 |
| 90 | 156 |
Draw a labelled solubility curve for calcium nitrate using the data.
State the dependent variable on the graph.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) — · must show points plotted correctly, axes labelled (Temperature/°C and Solubility/g per 100 g water), smooth curve or straight lines connecting points
(b) Solubility (g per 100 g water)
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Points plotted correctly and axes labelled with correct quantities and units
B2 (a) · 1 mark · Smooth curve or straight lines correctly joining the points (no bars)
B3 (b) · 1 mark · Identifies the dependent variable as solubility (g per 100 g water)
Worked solution
a) Plot temperature (°C) on the horizontal axis and solubility (g per 100 g water) on the vertical axis. Plot the five points and join them with a smooth curve or straight lines.
b) The dependent variable on the graph is solubility (g per 100 g water).