A 100-g block of copper is taken from a kiln and quickly placed into a beaker of negligible heat capacity containing 300 g of water.The water temperature rises from 15°C to 40°C.Given c_Cu = 0.10 cal/g·°C,and c_water = 1.00 cal/g·°C,what was the temperature of the kiln? A) 500°C B) 635°C C) 790°C D) 535°C

Question

Quizplus · Accepted Answer

We can use the principle of conservation of energy here to solve the problem. The heat lost by the copper block is equal to the heat gained by the water and the beaker. Let's assume that the initial temperature of the copper block was T°C. Then, the heat lost by the copper block is given by:
Q1 = cCu x mCu x (T - 40)
where cCu is the specific heat capacity of copper, mCu is the mass of copper, and T - 40 is the change in temperature of the copper block during the process.

The heat gained by the water and the beaker is given by:
Q2 = cwater x mwater x (40 - 15)
where cwater is the specific heat capacity of water, mwater is the mass of water, and 40 - 15 is the change in temperature of the water during the process.

Since the system is isolated and there are no other heat losses or gains, we can set Q1 equal to Q2 and solve for T:
cCu x mCu x (T - 40) = cwater x mwater x (40 - 15)
0.10 x 100 x (T - 40) = 1.00 x 300 x (40 - 15)
T - 40 = 750
T = 790°C

Therefore, the temperature of the kiln was 790°C.

A 100-G Block of Copper Is Taken from a Kiln