How many oxygen atoms are required to form two water molecules?
Answer and explanation
Correct answer: Two
The formula of water is \(\mathrm{H_2O}\), so each water molecule contains one oxygen atom. Therefore, two water molecules, \(2\mathrm{H_2O}\), contain two oxygen atoms. In the balanced equation \(2\mathrm{H_2}+\mathrm{O_2}\rightarrow2\mathrm{H_2O}\), one \(\mathrm{O_2}\) molecule supplies two oxygen atoms; hence the answer is two, not one.
Frequently asked questions
What is the correct answer to this question?
Two
Why is this the correct answer?
The formula of water is \(\mathrm{H_2O}\), so each water molecule contains one oxygen atom. Therefore, two water molecules, \(2\mathrm{H_2O}\), contain two oxygen atoms. In the balanced equation \(2\mathrm{H_2}+\mathrm{O_2}\rightarrow2\mathrm{H_2O}\), one \(\mathrm{O_2}\) molecule supplies two oxygen atoms; hence the answer is two, not one.
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.
