Final answer:
To calculate the total energy absorbed by benzene when heated from 25°C to 100°C and vaporized, one must use the specific heat capacity for heating to the boiling point and the enthalpy of vaporization for the phase change.
Step-by-step explanation:
To determine how much energy must be absorbed by benzene (C6H6) when it is heated from 25°C to become benzene vapor at 100°C, we need to calculate the total energy that involves both the heating of the liquid benzene to its boiling point and the vaporization of benzene at that temperature. The calculation requires two steps: (1) using the specific heat capacity of liquid benzene to find the energy needed to raise its temperature to the boiling point, and (2) using the enthalpy of vaporization to find the energy needed for phase change from liquid to vapor.
To calculate the energy for heating the liquid, we would use the formula q = m × c × ΔT, where q is the heat absorbed, m is the mass in grams, c is the specific heat capacity, and ΔT is the change in temperature. Then add the energy calculated from the enthalpy of vaporization using the formula q = m × ΔHvap, where ΔHvap is the enthalpy of vaporization per mole and m is the number of moles of benzene.
The sum of both values of q from the two processes will give us the total energy required for the benzene to be heated from 25°C to benzene vapor at 100°C.