Question

Calculate the heat réquired to convert $3 kg$ of ice at $-12^{\circ} C$ kept in a calorimeter to steam at $100^{\circ} C$ at atmospheric pressure. Given specific heat capacity of ice $=2100 Jkg ^{-1} K ^{-1}$, specific heat capacity of water $=4186 Jkg ^{-1} K ^{-1}$, latent heat of fusion of ice $=3.35 \times 10^{5} Jkg ^{-1}$ and latent heat of steam $=2.256 \times 10^{6} Jkg ^{-1}$

• A. $8.2 \times 10^{6} J$
• B. $9.1 \times 10^{6} J$
• C. $1.1 \times 10^{7} J$
• D. $2.6 \times 10^{7} J$

Answer 1

Answer: (B)

Heat required for
1. ice to go from $-12^{\circ} C$ to $0^{\circ} C$
2. ice to melt at $0^{\circ} C$
3. ice water to go from $0^{\circ} C$ to $100^{\circ} C$
4. ice water to vaporize at $100^{\circ} C$
$\Rightarrow Q=(3)(2100)(12)+(3)\left(3.35 \times 10^{5}\right) $
$+(3)(4186)(100)+(3)\left(2.256 \times 10^{6}\right)$
$=9.1 \times 10^{6} J$