A test tube with alcohol weighing 8 g was placed in hot water and, after a while, the alcohol boiled

A test tube with alcohol weighing 8 g was placed in hot water and, after a while, the alcohol boiled. How much heat is required to evaporate all the alcohol?

Initial data: m (mass of alcohol in a test tube) = 8 g.

Reference data: L (specific heat of vaporization of alcohol, ethyl alcohol) = 840 kJ / kg = 840 * 10 ^ 3 J / kg.

SI system: m = 8 g = 8 * 10 ^ -3 kg.

The amount of heat required for the complete evaporation of alcohol is calculated using the formula: Q = L * m.

Let’s perform the calculation: Q = 840 * 10 ^ 3 * 8 * 10 ^ -3 = 6720 J = 6.72 kJ.

Answer: For the complete evaporation of 8 g of alcohol, 6.72 kJ of heat is required.