What energy is required to melt 0.20 kg of ice at 0°C?

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Multiple Choice

What energy is required to melt 0.20 kg of ice at 0°C?

Melting ice at 0°C uses energy to overcome the forces holding the solid together, not to raise temperature—this is the latent heat of fusion. For ice, the latent heat of fusion is about 334 kJ per kilogram. Multiply by the mass: 0.20 kg × 334 kJ/kg = 66.8 kJ. The temperature stays at 0°C while melting, so all this energy goes into changing the phase. The other numbers don’t fit because they either scale the latent heat incorrectly (334 kJ/kg multiplied by 0.2 kg gives 66.8 kJ, not 6.68 or 334) or give an energy in joules that's too small for melting 0.2 kg.

Melting ice at 0°C uses energy to overcome the forces holding the solid together, not to raise temperature—this is the latent heat of fusion. For ice, the latent heat of fusion is about 334 kJ per kilogram. Multiply by the mass: 0.20 kg × 334 kJ/kg = 66.8 kJ. The temperature stays at 0°C while melting, so all this energy goes into changing the phase. The other numbers don’t fit because they either scale the latent heat incorrectly (334 kJ/kg multiplied by 0.2 kg gives 66.8 kJ, not 6.68 or 334) or give an energy in joules that's too small for melting 0.2 kg.

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