what mass of aluminum metal would absorb 250.0kj when it melted at its melting point? the molar enthalpy of fusion for aluminum is 10.71kj/mol

1 answer

To calculate the mass of aluminum that would absorb 250.0 kJ when it melts at its melting point, we need to use the molar enthalpy of fusion.

Given:
Enthalpy of fusion = 10.71 kJ/mol
Heat absorbed = 250.0 kJ

We know that 1 mole of aluminum will absorb 10.71 kJ of energy during the fusion process.
So, we can set up a proportion to find the number of moles of aluminum:

(10.71 kJ/1 mole) = (250.0 kJ/x moles)

Cross-multiplying the equation, we get:
10.71 kJ * x moles = 250.0 kJ

Simplifying the equation, we find:
x moles = 250.0 kJ / 10.71 kJ

Calculating the moles of aluminum:
x moles ≈ 23.34 moles

Since 1 mole of aluminum has a molar mass of 26.98 g, we can calculate the mass of aluminum:

Mass = moles × molar mass
Mass = 23.34 moles × 26.98 g/mol

Mass ≈ 629.35 g

Therefore, the mass of aluminum metal that would absorb 250.0 kJ when it melts at its melting point is approximately 629.35 grams.