During the decomposition of ( 14.2 mathrm{gm} ) of a mixture of calcium carbonate and magnesium
carbonate 3.36 litres of ( mathrm{CO}_{2} ) at S.T.P. are evolved. Determine the mass percents of
carbonates in the mixture.

( frac{x}{100}+frac{(14.2-x)}{84}=left(frac{3.36}{22.4}right) )
2) ( frac{84 x+1420-100 x}{8400}=left(frac{3.36}{22.4}right) )
2) ( frac{1420-16 x}{8400}=left(frac{3.36}{22.4}right) )
2) ( 31808-358.4 x=28224 )
2) ( 358.4 x geq 3584 )
( Rightarrow x=10 g )
( " cdot operatorname{Caco}_{3}=frac{10}{14.2} times 100=70.401 )
( % mathrm{Mg}left(0, frac{4.2}{14.2} times 100=29.5 right. )