Two hundred grams of a substance requires 18.8 kJ of heat to raise its temperature from 25°C to 45°C. Use the table to identify the substance. q = mCT. Mass (m) is in grams. Temperature is in degrees Celsius.

water

ammonia

gasoline

air

We are asked in the question to determine the substance given the heat required to achieve the temperature change and the mass of the substance. In this case, Cp is equal to q/m ΔT. substituting, 18.8 kJ / 200 g / 20 K equal to 4.7 J / g K. The closest is that of water which is 4.18 J / g K