Answer : The percent of aluminium in
is

Solution :
Molar mass of Aluminium = 26.98 g/mole
Molar mass of
= 342.15 g/mole
First we have to calculate the mass of Aluminium.
Mass of 2 Al atoms = 2 × 26.98 g/mole = 53.96 g/mole
Now we have to calculate the percent composition of Aluminium in


Now put all the given values in this formula, we get


Therefore, the percent of aluminium in
is
