# 7.6.2: Practice Stoichiometry part 2

Exercise $$\PageIndex{1}$$

2 Mg (s) + O2 (g) $$\rightarrow$$ 2 MgO (s)

In the reaction above, how many grams of MgO would be produced from 6.87 g of Mg and 5.22 g O2?

11.4 g MgO (Mg is limiting)

Exercise $$\PageIndex{1}$$

2 NH3 (g) + 3 O2 (g) $$\rightarrow$$ 3 H2O (g) + N2O3 (g)

In the reaction above, how many grams of N2O3 would be produced from 12.76 g of NH3 and 17.44 g O2?

13.81 g N2O3  (O2 is limiting)

In the reaction above, how many grams of N2O3 would be produced from 0.765 moles NH3 and 1.206 moles O2?

29.1 g  (NH3 is limiting)

Exercise $$\PageIndex{1}$$

2 HgO (s) $$\rightarrow$$ 2 Hg (l) + O2 (g)

If you heat 375.0 grams of HgO and obtain 248.4 g Hg, what is your percent yield?

71.52 %  (expect 347.3 g Hg product)

Exercise $$\PageIndex{1}$$

6 Li (s) + N2 (g) $$\rightarrow$$ 2 Li3(s)

If you heat 38.44 grams of Li (with plenty of nitrogen) and obtain 44.74 g Li3N, what is your percent yield?

69.57 %  (expect 64.31 g Li3N product)

Exercise $$\PageIndex{1}$$

Fe2S3 (s) + 6 HCl (g) $$\rightarrow$$  2 FeCl3 (s) + 3 H2S (g)

If you treat 17.82 grams of Fe2S3 (with plenty of HCl) and obtain 21.36 g FeCl3, what is your percent yield?