# Heat Curve Problems

1. How much heat is needed to warm 25 grams of water from 10 °C to 20 °C?

2. How much heat is needed to warm 25 grams of water from -10 °C to 20 °C?

3. What is the specific heat of copper metal if 200 cal increases the temperature of 40.9 g of it from 21 °C to 73 °C?

4. How much heat is needed to increase the temperature of 12 grams of gold from 20 °C to 95 °C?

5. What is the temperature of 40 grams of water at 45 °C added to 60 grams of water at 95 °C?

6. What mass of live steam at 100 °C is needed to heat 27.5 kg of water from 20 °C to 100 °C?

7. A 1.1 kg (1100 gram) iron horse shoe at 1300 °C is dunked into a bucket containing 12.8 kg of water at 20 °C. Assume that no steam was lost. (All of the steam leaves its heat of vaporization and its mass to the water in the bucket.) The horse shoe is taken out at 100 °C, just after it has quit boiling the water immediately around it. What is the new temperature of the bucket of water?

## Answers

1. 250 cal | 2. 2600 cal or 2.6 kcal | 3. 0.094 cal/g deg | 4. 29 cal |

5. 75 °C | 6. 4074 grams | 7. 36 °C | |