Chapter 2: Solubility Part 1 Page 2 SABIS Grade 11 (Level M) Chemistry

2.1.3 Factors That Fix The Solubility Of A Solid

Solubility curves

The graph below shows the solubility of potassium nitrate, hydrated copper (II) sulfate, sodium chloride and potassium sulfate in water. The vertical axis shows the solubility (mass of solute dissolved per 100 g of solvent) and the horizontal axis shows the temperature in degrees Celsius.

Using the graph, answer the following question.

What is the solubility of potassium nitrate at 20°C? At 50°C?

At 20°C, the solubility of potassium nitrate is

             Choose...             30 g/100 g water.             80 g/100 g water.         

At 50°C, the solubility of potassium nitrate is

             Choose...             30 g/100 g water.             80 g/100 g water.         

Using the graph, answer the following question:

By how much will the solubility of potassium nitrate increase if the temperature is increased from 20°C to 50°C? Give your answer to 2 significant figures.

The solubility of potassium nitrate will increase 

 g/100 g water.

Part 1 Page 3