Solution :-
mass of mixture = 42.500 g
mass of NH4Cl = 7.500 g
mass of SiO2 = 19.650 g
mass of NaCl = mass of mixture - [mass of NH4Cl + mass of
SiO2]
                     Â
= 42.500 g - [7.500 g +19.650 g]
                     Â
= 15.350 g
now lets find the percent of the each
% NH4Cl =( mass of NH4Cl/mixture mass )*100%
            Â
=(7.500g/42.500g)*100%
            Â
= 17.647 %
% SiO2 = =( mass of SiO2 /mixture mass )*100%
            Â
=(19.650 g / 42.500g)*100%
            Â
= 46.235 %
%NaCl = =( mass of NaCl/mixture mass )*100%
            Â
=(15.35 g/42.500g)*100%
            Â
= 36.117 %
