Question

# 39 gm of an alloy of aluminum and magnesium when heated with excess of dil. HCI from magnesium chloride, aluminum chloride, and hydrogen. the evolved hydrogen collected at 0C has a volume of 44.8 liters at 1atm pressures. Calculate the composition of the alloy by moles.

Solution

let the mole of magnesium be ( x ) and mole of aluminium be

( mathrm{y} ) ( mathrm{Mg}+2 mathrm{Hcl}--mathrm{MgCL} 2+mathrm{H} 2 )

( mathrm{Al}+3 mathrm{Hcl}-mathrm{m} / mathrm{Cl} 3+1.5 mathrm{H} 2 )

NOW

( 24 x+27 y=39 )

( x+1.5 y=2 )

solving these two equation we get ( x=.5, y=1 )

percentage of magnesium=30.76%

percentage of lauminium=69.24 %