Question #fdbe9

1 Answer
Mar 5, 2016

Answer:

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 = "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 #"Al"# to grams of #"Al"#.

#"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"#