Unit 5 Review

LR / XS

100

Magnesium reacts with oxygen.

_____Mg + _____O₂ → _____MgO

If 8.0 g of Mg reacts with excess O₂, how many grams of MgO are produced?

13.3 g MgO

200

Hydrogen reacts with oxygen.

2H₂ + O₂ → 2H₂O

If 5.0 moles H₂ react with 1.5 moles O₂:

a) What is the limiting reactant?

b) How many moles of H₂O are formed?

O₂ is limiting and 3.0 moles H₂O?

300

Zn + 2HCl → ZnCl₂ + H₂

If 10.0 g Zn reacts with 8.0 g HCl:

a) What is the limiting reactant?

b) How many grams of H₂ are produced?

HCl is limiting and 0.22 g H₂

400

2Al + 3Cl₂ → 2AlCl₃

If 15.0 g Al reacts with 40.0 g Cl₂:

a) What is the limiting reactant?

b) How many grams of AlCl₃ are produced?

Al is limiting and 66.7 g AlCl₃

500

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

If 44.0 g propane reacts with 96.0 g oxygen:

a) What is the limiting reactant?

b) How many grams of CO₂ are formed?

O₂ is limiting and 79.2 g CO₂

Percent Yield

100

Theoretical yield = 25.0 g

Actual yield = 20.0 g

Percent yield?

80%

200

Calcium carbonate decomposes:

CaCO₃ → CaO + CO₂

If 50.0 g CaCO₃ produces 24.0 g CaO (actual), what is the percent yield?

85.7%

300

If theoretical yield is 100 g and percent yield is 60%, what was the actual yield?

60 g

400

2Na + Cl₂ → 2NaCl

If 10.0 g Na produces 12.0 g NaCl (actual), what is the percent yield?

89.3%

500

4Al + 3O₂ → 2Al₂O₃

If 20.0 g Al produces 30.0 g Al₂O₃ (actual), what is the percent yield?

70.0%?

ICE Tables

100

H₂ + Cl₂ → 2HCl

Start with 2 mol H₂ and 2 mol Cl₂.

How many moles of HCl are formed?

4 mol HCl

200

2H₂ + O₂ → 2H₂O

Start with 4 mol H₂ and 1 mol O₂.

How many moles H₂ remain?

2 mol H₂ remain

300

N₂ + 3H₂ → 2NH₃

Start with 2 mol N₂ and 3 mol H₂.

a) Limiting reactant?

b) Moles NH₃ formed?

H₂ is limiting and 2 mol NH₃

400

2CO + O₂ → 2CO₂

Start with 5 mol CO and 1 mol O₂.

How many moles CO₂ form?

2 mol CO₂

500

4Fe + 3O₂ → 2Fe₂O₃

Start with 8 mol Fe and 6 mol O₂.

How many moles Fe₂O₃ form?

4 mol Fe₂O₃

Moles & Conversions

100

How many moles are in 44.0 g CO₂?

1.00 mole CO₂

200

How many molecules are in 3.0 moles H₂O?

1.81 × 10²⁴ molecules

300

At STP, what volume does 2.5 moles of gas occupy?

56.0 L

400

What is the molarity of a solution made by dissolving 5.0 moles of NaCl in 2.0 L?

2.5 M

500

How many grams are in 2.0 × 10²³ molecules of O₂?

10.6 g O₂

Stoichiometry

100

2H₂ + O₂ → 2H₂O

If 10.0 g H₂ reacts with excess O₂, how many grams of H₂O are produced?

89.3 g H₂O

200

N₂ + 3H₂ → 2NH₃

If 6.02 × 10²³ molecules of H₂ react with excess N₂, how many molecules of NH₃ are produced?

4.01 × 10²³ molecules NH₃

300

CaCO₃(s) → CaO(s) + CO₂(g)

If 25.0 g CaCO₃ decomposes completely, how many liters of CO₂ are produced at STP?

5.60 L CO₂

400

AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

If 150.0 mL of 0.200 M AgNO₃ reacts with excess NaCl, how many grams of AgCl form?

4.30 g AgCl

500

2Al + 3Cl₂ → 2AlCl₃

If 3.00 × 10²³ molecules of Cl₂ react with excess Al, how many grams of AlCl₃ are produced?

44.5 g AlCl₃