Read the descriptions below of two substances and an experiment on each. Decide whether the result of the experiment tells you the substance is a pure substance or a mixture, if you can. Sample A is 100.mL of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL. The liquid is then cooled in the refrigerator. At 10.0°C crystals begin to appear. The temperature of the liquid continues to decrease as more crystals form, until at 6.2°C the liquid is entirely solid.

Sample B is a solid yellow cube with a total mass of 50.0g. The cube is put into a beaker filled with 250.mL of water. The cube collapses into a small pile of orange powder at the bottom of the beaker. When this powder is filtered out, dried and weighed, it has a total mass of 29.9g. If the experiment is repeated with 500.mL of water, the powder that's left over has a mass of 10.0g.