# Amixture was found to contain 1.50 g NH_4Cl, 0.80 g NaCl, and 1.20 g SiO_2. What is the percentage of sand in this mixture?

$\text{Percentage of sand}$ $=$ "Mass of sand"/"Mass of mixture"xx100%
$\text{Percentage of sand}$ $=$ (1.20*g)/(1.20*g+1.50*g+0.80*g)xx100% $\cong$ 30%?