Final question..

An alloy used in aircraft construction consists of aluminium, copper and magnesium. An 11.34g sample of alloy was treated with alkali to dissolve the aluminium, leaving a residue of mass 2.73g. This residue was treated with dilute hydrochloric acid solution to dissolve the magnesium. The remaining residue had a mass of 0.90g.

Calculate the percentage composition of alloy.

%X = [(mass X)/mass sample] x 100
mass sample = 11.34g

mass of each of the follwoing is X.
mass Al = 11.34 - 2.73 g = ??
mass Cu = 0.90 g
mass Mg = 2.73 - 0.90 = ??

Post your work if you get stuck.

Thank you!!