Question

1How much heat is needed to cause the following irreversible reaction? 200 g of liquid H2O at 50°C is heated to form 200 g of steam at 120°C

2  Calculate the amount of heat needed to increase the temperature of 300 grams of water at 15°C to 75°C.

3 How much heat must be added to 100 grams of ice at 0°C to form water at 0°C?

4 How much heat must be removed when 25 grams of steam at 100°C Is condensed to form liquid water at 100°C?

5 How much heat is absorbed by pouring 10 grams of 100°C liquid water on a student’s hand. The water is cooled to body temperature, 37°C. Assume that all of the heat is absorbed by the hand.

6 How much heat is absorbed by contacting 10 grams of 100°C steam by a student’s hand. The steam is condensed to liquid and then the liquid is cooled to body temperature, 37°C. Assume that all of the heat is absorbed by the hand.

Answer 1

2 g: 20 m蚵.tmL + m1.^o2 deter 200 60o Ca 18 000 二loox.go+ 100 x1x0 8000 Cal 2 13500 Oy I (100-37