When air is blown from mouth into a test tube containing limewater, the limewater turns milky. This is due to the presence of
water vapour
oxygen
carbon dioxide
carbon monoxide
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CDS-1 – 2020
– The reaction is: Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l).
– Calcium carbonate (CaCO₃) is insoluble, causing the milky appearance.
– Human breath contains significant amounts of carbon dioxide.
CaCO₃(s) + H₂O(l) + CO₂(g) → Ca(HCO₃)₂(aq)