Question

sodium sulfate has the formula NA2SO4. a)what is the mass percentage of each element in sodium sulfate? b) how many grams of this compound contain 2.00grams sulfur

Answer 1

assuming 1 mol of Na2SO4, where its molar mass is 142 g/mol

%Na = [( 1 mol Na2SO4 ) ( 2 mol Na / 1 mol Na2SO4) ( 23 g Na / 1 mol Na) / ( 1 mol Na2SO4) ( 142 g /mol)] * 100
%Na = 32.39 %

% S = ( 1 mol Na2SO4 ) ( 1 mol S / 1 mol Na2SO4) ( 32 g S / 1 mol Na) / ( 1 mol Na2SO4) ( 142 g /mol)] * 100
%S = 22.54 %

% O = ( 1 mol Na2SO4 ) ( 4 mol O / 1 mol Na2SO4) ( 16 g O / 1 mol Na) / ( 1 mol Na2SO4) ( 142 g /mol)] * 100
% O = 45.07 %