STUDENT SPACE · TOPIC 1
Solutions and purity
Distinguish solutions from suspensions and use melting data to assess purity.
The essentials
- A solute dissolves in a solvent to form a solution.
- A pure substance contains one substance; a mixture contains more than one.
- At a stated pressure, a pure substance has a characteristic melting or boiling point. Impurities usually lower and broaden the melting range.
Key vocabulary
| English | Chinese |
|---|---|
| solute | 溶质 |
| solvent | 溶剂 |
| solution | 溶液 |
| impurity | 杂质 |
Quick practice
A solid melts gradually from 61 °C to 66 °C. What does this suggest about its purity?
Need a hint?
Compare a sharp melting point with a melting range.
Check your reasoning after trying
The melting range suggests the solid is impure. A pure solid normally melts sharply at its characteristic melting point.
Use Lesson 1 in your worksheet for written practice. Your teacher will discuss those answers in class.