Question

A scientist is comparing 2 samples of the same compound. One is pure and the other is impure. The compound is a solid at room temperature. Explain how the scientist could tell which is the pure compound. [2]

Answer 1

A glass of mineral water is not pure water.

Step-by-step explanation:

Pure chemical substances

Pouring water into a glass from a bottle

Food and drink may be advertised as ‘pure’. For example, you may see cartons of ‘pure orange juice’ or ‘pure mineral water’. This means that nothing else was added to the orange juice or mineral water during manufacture. However, these substances are not pure to a scientist. In science, a pure substance contains only one element or compound.

Mineral water is mostly water, but there are other substances mixed with it. These are the ingredients that you see listed on the bottle’s label.