Question

Ethyl chloride, C₂H₅Cl, is used as a local anesthetic. It works by cooling tissue as it vaporizes; its heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 10.0 g of ethyl chloride?

Answer 1

To determine the heat removed by 10.0 g of ethyl chloride, convert the mass to moles using its molar mass and then multiply by the heat of vaporization. The result is that 10.0 g of ethyl chloride can remove 4.092 kJ of heat.

Step-by-step explanation:

Calculating Heat Removal by Ethyl Chloride

To find how much heat could be removed by 10.0 g of ethyl chloride (C₂H₅Cl), we need to use the given heat of vaporization and the mass of ethyl chloride. The heat of vaporization is the amount of energy required to convert one mole of a substance from a liquid to a gas at constant temperature and pressure. For ethyl chloride, this value is 26.4 kJ/mol.

First, convert the mass of ethyl chloride to moles using its molar mass, which is approximately 64.5 g/mol:

1. Number of moles = (Mass in grams) / (Molar mass) = 10.0 g / 64.5 g/mol = 0.155 mol
2. Then, calculate the heat absorbed during vaporization: Heat absorbed (in kJ) = (Number of moles) × (Heat of vaporization) = 0.155 mol × 26.4 kJ/mol = 4.092 kJ

Therefore, 10.0 g of ethyl chloride can remove 4.092 kJ of heat as it vaporizes.