Q.)An ice-cube tray holding 0.250 kg of water at 20°C is placed in a freezer. If the freezer withdraws heat from the water at a rate of 2,000 J/min, how long will it take to completely freeze the water into solid ice cubes?

A.)The heat absorbed during melting is the same amount as the heat released during freezing, so the equation q=mHf still applies. The heat removed is the sum of the heat needed to cool the water to freezing (q=mCΔT) and the heat removed to freeze the water (q=mHf). q=mCΔTqtemp=(0.250kg)×(4,180Jkg⋅K)×(293 K−273 K)<--- where did this come from qtemp=(0.250kg)×(4,180Jkg⋅K)×(20 K)...... qtemp=20,900 J=2.09×104 J