`30-`volume hydrogen peroxide means

Options

A. `30 %` of `H_(2)O_(2)` by volume
B. `30 g` of `H_(2)O_(2)` solution contains `1g` of `H_(2)O`
C. ` 1 cm^(3)` of solution liberates `30 cm^(3)` of dioxygen gas at STP
D. `1 cm^(3)` of solution liberate `30 cm^(3)` of dioxygen gas at `STP`

Answer

To understand what "30-volume hydrogen peroxide" means, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding Volume of Hydrogen Peroxide**:
- The term "30-volume" refers to the amount of oxygen gas that can be liberated from a given volume of hydrogen peroxide solution. Specifically, it indicates how many volumes of oxygen gas are produced from 1 volume of hydrogen peroxide solution.

2. **Chemical Reaction**:
- The decomposition of hydrogen peroxide can be represented by the following balanced chemical equation:
\[ 2 \text{H}_2\text{O}_2 \rightarrow 2 \text{H}_2\text{O} + \text{O}_2 \]
- From this equation, we see that 2 moles of hydrogen peroxide decompose to produce 1 mole of oxygen gas.

3. **Volume Relationship**:
- At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 liters. Therefore, if 2 moles of H₂O₂ produce 1 mole of O₂, then:
- 2 liters of H₂O₂ will produce 1 liter of O₂.
- Consequently, 1 liter of H₂O₂ will produce 30 liters of O₂.

4. **Conversion to Milliliters**:
- Since 1 liter is equivalent to 1000 milliliters (ml), we can deduce that:
- 1 ml of H₂O₂ will produce 30 ml of O₂.
- This means that for every 1 cm³ (which is equal to 1 ml) of hydrogen peroxide solution, 30 cm³ of oxygen gas is liberated.

5. **Conclusion**:
- Therefore, "30-volume hydrogen peroxide" means that 1 cm³ of the hydrogen peroxide solution will liberate 30 cm³ of dioxygen gas at STP. This corresponds to option C from the original question.

### Final Answer:
**30-volume hydrogen peroxide means that 1 cm³ of the solution liberates 30 cm³ of dioxygen gas at STP.**

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