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Reviewed CSCA Chemistry question · Standard

在恒温恒容密闭容器中,发生反应:2A(g) + B(g) ⇌ 2C(g)。起始时充入 4 mol A 和 2 mol B,达到平衡时测得 C 的物质的量为 2.4 mol。则 B 的转化率为多少?

  1. 60%
  2. 40%
  3. 80%
  4. 20%
Show the answer and explanation

Correct answer

A. 60%

Principle or equation

转化率 = 转化的物质的量 / 起始物质的量 × 100%。根据化学计量数计算。

Why this answer is correct

生成 2.4 mol C,消耗 B 的物质的量 = 2.4 mol / 2 = 1.2 mol;B 的转化率 = 1.2 / 2 × 100% = 60%。

Example

若生成 1.6 mol C,则消耗 B 0.8 mol,转化率 40%。

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