Question

P-xylene, c8h10, has an enthalpy of fusion of 158.3 j g-1 and its melting point temperature is 13.2°c. how much heat is required to transform 115 g of solid p-xylene at 13.2°c into liquid p-xylene, also at 13.2°c?

Answer 1

Answer:

$\boxed{\text{18.2 kJ}}$

Explanation:

The formula for the heat involved is  

$q = m\Delta_{\text{f}}\text{H}$

Data:

m = 115 g

$\Delta_{\text{f}}\text{H} = \text{158.3 J/g}$

Calculation:

$q = \text{115 g} \times \dfrac{\text{158.3 J}}{\text{1 g}}\\\\q = \text{18 200 J} = \textbf{18.2 kJ}}\\\\\text{It takes }\boxed{\textbf{18.2 kJ}} \text{ to melt the p-xylene}$