Stoichiometry Review

Stoichiometry A

1

2 Al + Fe₂O₃  -> 2 Fe + Al₂O₃

If you start with 50.0g of Fe₂O₃ , what mass in grams of Fe can be produced?

Fe = 56 g/mol      Fe₂O₃ = 160 g/mol

35.0 g Fe

1

2 KClO₃  -> 2 KCl + 3 O₂

How many moles of O₂ can be produced from the decomposition 4.90 grams of KClO₃

_{KClO3 = 122.5 g/mol      O2 = 32 g/mol}

0.06 mol

1

2 KClO₃  -> 2 KCl + 3 O₂

If you start with 9.03 x 10²² molecules of O₂ , what mass in grams of KCl is needed?

KCl = 74.5 g/mol      O₂ = 32 g/mol

7.43 g

1

2 Na  +  Cl₂ -> 2 NaCl

If you start with 10.0g of Na , what mass in grams of NaCl can be produced?

NaCl = 58.5 g/mol      Na = 23 g/mol

25.4 g

1

2 KClO₃  -> 2 KCl + 3 O₂

If you start with 1.5g of KClO₃ , how many molecules of O₂ can be produced?

KClO₃ = 122.5 g/mol      O₂ = 32 g/mol

1.11 x 10²² molecules

Stoichiometry B

1

P₄ + 6 H₂  ->  4 PH₃

If you start with 5g of P₄ , how many molecules of PH₃ can be produced?

P₄ = 124 g/mol      PH₃ = 34 g/mol

9.72 x 10²² Molecules

1

2 KClO₃  -> 2 KCl + 3 O₂

If you start with 25.0g of KClO₃ , what mass in grams of KCl can be produced?

KCl = 74.5 g/mol      KClO₃ = 122.5 g/mol

15.2 g

1

2 Al + Fe₂O₃  -> 2 Fe + Al₂O₃

If you start with 10.8 g of Al , how many molecules of Al₂O₃ can be produced?

Al = 27 g/mol      Al₂O₃ = 102 g/mol

1.21 x 10²³ molecules

1

P₄ + 6 H₂  ->  4 PH₃

How many grams of H₂ are required to produce 2.50 moles of PH₃

H₂ = 2 g/mol      PH₃ = 34 g/mol

7.58 g

1

2 Na  +  Cl₂ -> 2 NaCl

If 20.0g NaCl is produced, how many moles of Na reacted?

NaCl = 58.5 g/mol      Na = 23 g/mol

0.342 mol Na