1. Understand the Concepts
* Heat of Vaporization: This is the amount of energy needed to change a substance from a liquid to a gas at its boiling point. For toluene, the heat of vaporization is approximately 380 J/g.
* Mass: The amount of substance you are working with (5 grams in this case).
2. Calculation
Energy (Q) = mass (m) × heat of vaporization (ΔHvap)
Q = 5 g × 380 J/g
Q = 1900 J
Therefore, approximately 1900 Joules of energy are required to evaporate 5 grams of toluene.
Important Note: This calculation assumes the toluene is already at its boiling point. If the toluene is at a lower temperature, you would need to first calculate the energy required to raise its temperature to the boiling point before adding the energy required for vaporization.
