Question

Calculate the amount of heat (in calories) required to convert $5\, g$ of ice at $0^{\circ}C$ to steam at $100^{\circ}C$ .

• A. 3100
• B. 3200
• C. 3600
• D. 4200

Answer 1

Answer: (C)

3600

Answer 2

Total heat required =heat required to convert ice into water at $0^{\circ} C\left(Q_{1}\right)+$
heat required to increase the temperature of water upto $100^{\circ} C\left(Q_{2}\right)+$
heat required to convert water into steam at $100^{\circ} C\left(Q_{3}\right)$
$=Q_{1}=m L=5 \times 80=400\, cal$
$=Q_{2}=m s \Delta t=5 \times 1 \times(100-0)=500\, cal$
$=Q_{3}=m L=5 \times 540=270\, cal$
$=Q=Q_{1}+Q_{2}+Q_{3}=400+500+2700$
$=3600\, cal$