# Question fdbe9

Mar 5, 2016

You are correct! The mass of aluminium would be 629.8 g.

#### Explanation:

The formula for the amount of heat transferred is

q = nΔ_"fus"H

where

• $q$ is the amount of heat transferred
• $n$ is the number of moles of substance
• Δ_"fus"H is the molar enthalpy of fusion of the substance

$q = \text{250.0 kJ}$

Δ_"fus"H = "10.71 kJ·mol"^"-1"

n = q/(Δ_"fus"H) = (250.0 color(red)(cancel(color(black)("kJ"))))/(10.71 color(red)(cancel(color(black)("kJ")))"·mol"^"-1") = "23.343 mol"#

Now, we must convert moles of $\text{Al}$ to grams of $\text{Al}$.

$\text{Mass of Al" = 23.343 color(red)(cancel(color(black)("mol Al"))) × "26.982 g Al"/(1 color(red)(cancel(color(black)("mol Al")))) = "629.8 g Al}$