How much heat needs to be spent to melt a piece of lead weighing 100 g, taken at the melting temperature.

If a piece of lead was taken at the melting temperature (327 ºС), then the amount of heat spent on melting can be calculated by the formula:
Q = λ * m, where λ is the specific heat of fusion of lead (λ = 0.25 * 10 ^ 5 J / (kg * K)), m is the mass of a piece of lead (m = 100 g = 0.1 kg).
Let’s calculate the amount of heat spent on melting:
Q = λ * m = 0.25 * 10 ^ 5 * 0.1 = 2500 J = 2.5 kJ.
Answer: It is necessary to spend 2.5 kJ of heat.