2020 · Q17
When air is blown from mouth into a test tube containing limewater, the limewater turns milky. This is due to the presence of
General KnowledgeChemistry
- AWater vapour
- BOxygen
- CCarbon dioxide
- DCarbon monoxide
Explanation
Exhaled air contains carbon dioxide. Carbon dioxide reacts with limewater (calcium hydroxide solution) to form insoluble calcium carbonate, which turns the limewater milky. Water vapour, oxygen and carbon monoxide do not produce this effect. Hence C.