During electrolysis of water, at the same temperature and pressure, if the volume of oxygen collected is 7 mL, what volume of hydrogen will be collected?
Answer and explanation
Correct answer: 14 mL
The balanced equation for electrolysis of water is \(2H_2O \rightarrow 2H_2 + O_2\). At the same temperature and pressure, gas volumes are proportional to their mole ratios. Therefore, the volume ratio of hydrogen to oxygen is \(2:1\). For 7 mL of oxygen, the volume of hydrogen is \(2 \times 7 = 14\) mL. The value 21 mL would result from incorrectly using a \(3:1\) ratio.
Frequently asked questions
What is the correct answer to this question?
14 mL
Why is this the correct answer?
The balanced equation for electrolysis of water is \(2H_2O \rightarrow 2H_2 + O_2\). At the same temperature and pressure, gas volumes are proportional to their mole ratios. Therefore, the volume ratio of hydrogen to oxygen is \(2:1\). For 7 mL of oxygen, the volume of hydrogen is \(2 \times 7 = 14\) mL. The value 21 mL would result from incorrectly using a \(3:1\) ratio.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
