Solubility curves

2 marks · Normal

The solubility of sodium carbonate in water at 10°C is 12 g per 100 g of water, and at 30°C is 18 g per 100 g of water. What would be the solubility at 30°C in 50 g of water? Give your answer in grams. Show your calculation.

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

9 g (±0.1)

Must show: Sets up the correct calculation, Writes the answer in grams

Also accept: 9.0; 9

Common mistakes: Forgetting to divide by 2

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Sets up calculation: (18/100) × 50 or (18 × 0.5).

A1 · 1 mark · Answers correctly: 9 g (with or without units).

Worked solution

Maximum that dissolves = (solubility per 100 g water) × (mass of water / 100)