中考化学：水、溶液与溶解度基础
A middle-school chemistry practice set on water, solutions, and solubility: the composition of water, hard vs. soft water, solution properties, saturation/unsaturation, and reading solubility curves.
- Explain the elemental and molecular composition of water
- Distinguish hard water from soft water using soap water
- Determine whether a solution is saturated or unsaturated given solubility data
- Read and interpret solubility curve intersections and trends
中考化学：水、溶液与溶解度基础 — 水的组成、硬水软水、溶液概念与溶解度曲线判读。
示例问题
在电解水的实验中，已知正极产生氧气，负极产生氢气。若实验中产生氧气的体积为 5 mL，则同时产生的氢气体积约为多少？
- 5 mL
- 10 mL
- 2.5 mL
- 15 mL
查看答案
10 mL
根据电解水反应方程式 $2\text{H}_2\text{O} \xrightarrow{\text{通电}} 2\text{H}_2\uparrow + \text{O}_2\uparrow$，氢气与氧气的体积比为 2:1。因此，氧气为 5 mL 时，氢气应为 10 mL。