Density of water =1000 Kg m-3 Conversion : 1L ≡ 103 g for water 1) A 12.5 g sample of an unknown metal, heated to 99.0 °C was then plunged into 50.0 mL water at 25.0 °C . The final temperature of the water and metal was 28.1 °C. Assuming no loss of energy to the surroundings calculate:

a) How many joules of energy did the water absorb?

b) How many joules of energy did the metal lose?

c) What is the heat capacity of the metal?

d) What is the specific heat capacity of metal?

2) A 0.400 kg aluminum kettle contains 2.00 kg of water at 15.0 oC. How much heat is required to raise the temperature of the water (and kettle) to 100 C?

3) You go to kitchen to boil water. You pour 280 gram of water to a container, and put the container on a 293 W electric heater. Assume that all the heat from the heater is used to heat the water.

a) If the temperature of the water is 21.6 °C before you turn on the heater, how long does it take for the water temperature to reach 100 °C after you turn on the heater? Provide your answers in minutes.

b) After the water temperature reached 100 °C, if you let the water keep boiling with the heater turn on for 20.0 minutes, how much water will be left in the container? Assume that all the vaporized water is removed from the container.

4) When a nuclear power plant’s reactor is shut down, radioactive decay continues to produce heat at about 10% of the reactor’s normal power level of 3.00x109W . In a major accident, a pipe breaks and all the reactor cooling water is lost. The reactor is immediately shut down, the break sealed, and 420 m3 of