Q. Calculate the amount of heat (in calories) required to convert $5 g$ of ice at $0^{\circ} C$ to steam at $10 0^{\circ} C$ .

2904 220 Delhi UMET/DPMTDelhi UMET/DPMT 2005Thermal Properties of Matter Report Error

A

3100

8%

B

3200

23%

C

3600

52%

D

4200

17%

Solution:

Total heat required =heat required to convert ice into water at $0^{\circ} C (Q_{1}) +$
heat required to increase the temperature of water upto $10 0^{\circ} C (Q_{2}) +$
heat required to convert water into steam at $10 0^{\circ} C (Q_{3})$
$= Q_{1} = m L = 5 \times 80 = 400 c a l$
$= Q_{2} = m s Δ t = 5 \times 1 \times (100 - 0) = 500 c a l$
$= Q_{3} = m L = 5 \times 540 = 270 c a l$
$= Q = Q_{1} + Q_{2} + Q_{3} = 400 + 500 + 2700$
$= 3600 c a l$