posted by hope .
A mixture contains only NaCl and Al2(SO4)3. A 1.76-g sample of the mixture is dissolved in water, and an excess of NaOH is added, producing a precipitate of Al(OH)3. The precipitate is filtered, dried, and weighed. The mass of the precipitate is 0.126 g. What is the mass percent of Al2(SO4)3 in the sample?