How much heat is required to melt 1.5 kg of zinc, the initial temperature of which is 200 ° C?

Given:

m = 1.5 kilograms is the mass of zinc;

T0 = ​​200 degrees Celsius – initial zinc temperature;

q = 120,000 J / kg is the specific heat of fusion of zinc;

c = 380 J / (kg * C) – specific heat of zinc;

T = 420 degrees Celsius is the melting point of zinc.

It is required to determine Q (Joule) – the energy required to melt zinc.

Let’s find the energy to heat zinc from its initial temperature to its melting point:

Q1 = c * m * (T1 – T0) = 380 * 1.5 * (420 – 200) = 570 * 220 = 125400 Joules.

Let’s find the energy to melt zinc:

Q2 = q * m = 120,000 * 1.5 = 180,000 Joules.

Then the total energy will be equal to:

Q = Q1 + Q2 = 125400 + 180000 = 305400 Joules.

Answer: the energy will be equal to 305400 Joules.