Answer: The amount of heat needed to raise a substance's temperature by one Kelvin per kilogram. The heat needed to raise the temperature of a given substance with known mass can be calculated as follows:
ΔH=mCΔT
ΔH=Amount of heat energy supplied
m=Mass of the substance = 15 g
ΔT=Change in temperature = Tfinal−Tinitial = 250° C - 275.0°C = -25°C
C=Specific heat capacity = 2.02 J/g °C
ΔH=mCΔT
after putting the given values,
ΔH= -757.5 J
The formula also shows that heat energy is released (negative value) when the change in temperature is negative, i.e., when the temperature of a substance falls.