How much heat must be spent to melt a body of mass m heated to a melting temperature of hydrogen 0.7.

Problem data: m (mass of taken hydrogen) = 0.7 kg; hydrogen is at its melting point (-259.14 ºС).

Reference values: λ (specific heat of fusion of hydrogen) = 0.59 * 10 ^ 5 J.

The amount of heat spent on melting 0.7 kg of hydrogen is determined by the formula: Q = λ * m.

Let’s make a calculation: Q = 0.59 * 10 ^ 5 * 0.7 = 0.413 * 10 ^ 5 J = 41.3 kJ.

Answer: To melt 0.7 kg of hydrogen, 41.3 kJ of heat is required.