Question

What amount of heat is exchanged when 106.2 grams of substance Y goes from a liquid at 35 degrees Celsius to a solid at the same temperature? Melting point of substance Y = 35 degrees C; ΔHvaporization = 3.67 J/mol; ΔHfusion = 3.30 J/mol. MWsubstance y = 28.22 g/mol. −12.4 J −3.51 x 102 J 1.24 x 101 J 351 J

Answer 1

-12.4 J

Step-by-step explanation:

Given data:

Mass of substance = 106.2 g

Melting point = 35°C

Molar weight = 28.22 g/mol

Heat of fusion = 3.30 j/mol

Heat of vaporization = 3.67 j/mol

Amount of heat exchanged = ?

Solution:

First of all we will calculate the number of moles.

Number of moles = mass/ molar mass

Number of moles = 106.2 g/ 28.22 g/mol

Number of moles = 3.76 mol

Amount of heat exchanged = 3.76 mol ×3.30 j/mol

Amount of heat exchanged = 12.4 J

So option A is correct. Heat is released that's why" - " is added with answer.

Amount of heat exchanged = -12.4 J