How much heat is needed to raise the temperature of ice from -25°C to 0°C?

• A. 1.09 kJ/kg K
• B. 2.09 kJ/kg K
• C. 3.09 kJ/kg K
• D. 4.09 kJ/kg K

Answer: (B)

To determine the amount of heat required to raise the temperature of ice from -25°C to 0°C, it is necessary to consider the specific heat capacity of ice. The specific heat capacity is the amount of heat needed to raise the temperature of a unit mass of a substance by one degree Celsius (or one Kelvin).

For ice, the specific heat capacity is approximately 2.09 kJ/kg K. When you raise the temperature of ice from -25°C to 0°C, you are increasing the temperature by 25 degrees. The heat required can be calculated using the formula:

Q = mcΔT

where:

• Q is the heat energy (in kJ),

• m is the mass of the ice (in kg),

• c is the specific heat capacity (in kJ/kg K),

• ΔT is the change in temperature (in K or °C).

If we define the mass of ice as 1 kg for simplicity, then:

Q = 1 kg × 2.09 kJ/kg K × 25 K = 52.25 kJ.

However, the specific heat capacity required for raising the temperature from -25°C to 0°C remains 2.09 kJ/kg K because this