Question

 Given 4Ga(s) + 3O2(g) ? 2Ga2O3(s), what mass of gallium oxide could be prepared from 5.00 g of gallium metal?

Answer 1

Moles of gallium = $\frac{5.00}{70}=0.07moles$

Moles of gallium oxide $=\frac{2}{4}×0.07=0.035moles$

Mass of gallium oxide $=187×0.035=6.545grams$