# How much heat is required to melt 3 kg of ice taken at a temperature of -20C?

We give all the values from given in the SI system:

t1 = -20 C = 253 K

1. The amount of heat spent on heating the body is equal to the product of the specific heat capacity of the substance, body weight and the difference between the final and initial temperatures.

Q = c * m * (t2-t1), where c is the specific heat capacity of the substance, m is the mass of the substance, t2 and t1 are the final and initial temperatures, respectively.

The specific heat capacity of ice is c = 2100 J / kg * K, the melting point of ice is 0 C = 273 K.

Substituting numerical data into the formula, we get:

Q = c * m * (t2-t1) = 2100 * 3 * (273-253) = 126000 J

To heat ice to the melting temperature, 126 kJ of heat must be spent.

2. To melt the ice, the required amount of heat:

Q = λ * m, where λ is the specific heat of fusion of the substance, m is the mass of the substance.

Specific heat of melting of ice λ – 3.3 * 10 ^ 5 J / kg

Substituting numerical data into the formula, we get:

Q = λ * m = 330,000 * 3 = 1,020000 J

3. The total amount of heat:

Q = Q1 + Q2 = 126000 + 1020000 = 1146000 J

Answer: 1146000 J of heat or 1146 kJ is required