How much heat is needed to change 3kg of copper from a solid to a liquid? Heat of fusion = 205,000 J/kg

q = mass Cu x heat fusion Cu

To calculate the amount of heat needed to change copper from a solid to a liquid, we need to use the formula:

Q = m * Hf

Where:
Q is the amount of heat required
m is the mass of the substance
Hf is the heat of fusion, which is the amount of heat required to change a substance from a solid to a liquid without changing its temperature. For copper, the heat of fusion is 205,000 J/kg.

Given:
m = 3 kg
Hf = 205,000 J/kg

Plugging in the values into the formula:

Q = 3 kg * 205,000 J/kg

Q = 615,000 J

Therefore, 615,000 Joules of heat are needed to change 3 kg of copper from a solid to a liquid.