When water is heated from 0°C to 4°C, its density
[amp_mcq option1=”remains constant.” option2=”increases.” option3=”decreases.” option4=”first increases then decreases to its original value.” correct=”option2″]
This question was previously asked in
UPSC CDS-2 – 2022
The correct answer is B) increases.
Water exhibits anomalous expansion between 0°C and 4°C. Unlike most substances whose density decreases upon heating (as volume increases), water’s volume *decreases* when heated from 0°C to 4°C. Density is mass per unit volume (ρ = m/V). Since the mass remains constant and the volume decreases in this temperature range, the density of water increases.