Question

Calculate the heat that must be supplied to a copper kettle of mass 400.0 g containing 300.0 g of water to raise its temperature from 20.0 °c to the boiling point of water, 100.0 °c. (b) what percentage of the heat is used to raise the temperature of the water?

Answer 1

To calculate the heat that must be supplied to the copper kettle, use the formula Q = mcΔT. The percentage of heat used to raise the temperature of the water is 12.4%.

Step-by-step explanation:

To calculate the heat that must be supplied to the copper kettle, we need to use the formula:

Q = mcΔT

Where:

• Q is the heat
• m is the mass
• c is the specific heat capacity
• ΔT is the change in temperature

For the copper kettle:

• m = 400.0 g
• c = specific heat capacity of copper (0.39 J/g•°C)
• ΔT = 100.0 °C - 20.0 °C = 80.0 °C

Plugging these values into the formula:

Q = (400.0 g)(0.39 J/g•°C)(80.0 °C) = 12,480 J

To calculate the percentage of heat used to raise the temperature of the water, we need to know the heat capacity of the water. The heat capacity of water is approximately 4.18 J/g•°C.

For the water:

• m = 300.0 g
• c = 4.18 J/g•°C
• ΔT = 100.0 °C - 20.0 °C = 80.0 °C

Plugging these values into the formula:

Q = (300.0 g)(4.18 J/g•°C)(80.0 °C) = 100,320 J

So, the percentage of heat used to raise the temperature of the water is:

Percentage = (12,480 J / 100,320 J) x 100% = 12.4%