How much heat must be removed from 500 grams of water at 0°C to form ice at 0°C?

q = mass H2O x heat fusion H2O

To calculate the amount of heat that must be removed from water to form ice, we can use the equation:

Q = m * ΔHf

Where:
Q is the heat energy in joules needed to change the phase
m is the mass of the substance in grams
ΔHf is the heat of fusion, which is the amount of energy needed to change the phase of a substance from solid to liquid or from liquid to solid at its melting/freezing point.

For water, the specific heat of fusion (ΔHf) is 334 J/g. This means that it takes 334 joules of energy to change the phase of 1 gram of water from liquid to solid at 0°C.

Let's now calculate the heat energy needed to change the phase of 500 grams of water:

Q = 500 g * 334 J/g
Q = 167,000 J

Therefore, 167,000 joules of heat energy must be removed from 500 grams of water at 0°C to form ice at 0°C.