When air is blown from mouth into a test tube containing limewater, the limewater turns milky. This is due to the presence of
[amp_mcq option1=”water vapour” option2=”oxygen” option3=”carbon dioxide” option4=”carbon monoxide” correct=”option3″]
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)