Why does sodium hydroxide not remain pure when kept in open air?
Answer and explanation
Correct answer: It is affected by both moisture and carbon dioxide
The governing concept is the deliquescent and reactive nature of sodium hydroxide. Solid NaOH absorbs moisture from air, so it becomes wet and its composition is altered. It also reacts with atmospheric carbon dioxide to form sodium carbonate: 2NaOH + CO2 → Na2CO3 + H2O. Thus option A is correct. Sodium hydroxide does not form gold with oxygen, does not make salt with nitrogen, and clearly does change in moist air.
Frequently asked questions
What is the correct answer to this question?
It is affected by both moisture and carbon dioxide
Why is this the correct answer?
The governing concept is the deliquescent and reactive nature of sodium hydroxide. Solid NaOH absorbs moisture from air, so it becomes wet and its composition is altered. It also reacts with atmospheric carbon dioxide to form sodium carbonate: 2NaOH + CO2 → Na2CO3 + H2O. Thus option A is correct. Sodium hydroxide does not form gold with oxygen, does not make salt with nitrogen, and clearly does change in moist air.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
