A block of ice of mass 10kg at 0°C absorbs heat energy from its surroundings and changes to water at the same temperature. The heat absorbed is referred to as

Step 1: Analyze the question A 10 kg block of ice at 0°C absorbs heat and becomes water at 0°C. The temperature does not change; only the state changes (solid to liquid). So we need the name for heat absorbed during a change of state.

Step 2: Key concepts

• Heat capacity: heat needed to raise the temperature of a whole body by 1 K (J/K).
• Specific heat capacity: heat needed to raise 1 kg of a substance by 1 K (J/kg·K).
• Latent heat: the heat absorbed or released by a body of any mass during a change of state at constant temperature (unit: J).
• Specific latent heat: the heat absorbed or released by 1 kg of a substance during a change of state at constant temperature (J/kg).

Step 3: Apply to the question

• There is no temperature change, so options A, C and D (all about temperature rise) are ruled out.
• The question asks about the heat absorbed by a 10 kg block, not per kilogram. This is the total heat, Q = mL = 10 × L (for ice, L ≈ 3.34 × 10⁵ J/kg, so Q ≈ 3.34 × 10⁶ J).
• The total heat absorbed by the given mass is the latent heat. Specific latent heat (E) would be the value per 1 kg, which is not what is described here.

Step 4: Answer The heat absorbed by the 10 kg of ice during melting is the latent heat (of fusion), which is option B.

Exam tip: Look at whether the question mentions a specific mass or "per unit mass".

• Total heat for a given mass during a state change → latent heat (Q = mL).
• Heat per kilogram → specific latent heat (L).
• No temperature change → it is never about "specific heat" or "heat capacity".