Question

If a sample of chloroform is initially at 25°C, what is its final temperature if 1.5 kg of chloroform absorbs 1.0 kilojoules of heat, and the specific heat of chloroform is 960 J/kg C?

Answer 1

Here, we're relating a few things: (1) the mass of the substance, (2) its specific heat, and (3) the temperature change, with the following equation:

`q = mC_sDeltaT`

Here, we aren't given the temperature change, but we are given the energy absorbed (and hence, a positive sign). Let's translate this first, for an easier calculation

`1.0kJ*(1000J)/(kJ) = 10^3 J`

`10^3 J = 1.5 kg * (960J)/(kg*°C)*DeltaT`

Some quick algebra, and we have:

`DeltaT = 6.9*10^-1°C`

From here, we'd like to add this quantity to the initial temperature, `T_i`, in order to realize our answer:

`T_f approx 25.7°C`