Question

80 g of water at ${30}^{\circ }C$ are poured on a large block of ice at $0^{\circ }C$ The mass of ice that melts is

• A. 30 g
• B. 80 g
• C. 1600 g
• D. 150 g

Answer 1

The correct option is A 30 g

Heat contained in water

$Q=ms\Delta T$ $(s=1cal/gm{/}^{o}C)$

$Q=80\times 1\times (30-0)$

$Q=2400$Cal

Then, heat gained by ice will be same

$Q=2400$

$L_f\times M=2400$ $(L_f=80cal/gm)$

$M=\frac{2400}{80}$

$M=30gm$

Thus, $30$gm of ice is melted.