Stoichiometry Practice Problems

Nitrogen combines with oxygen to yield nitric oxide.

N₂(g) + O₂(g) → 2 NO(g)

Determine the number of moles of NO produced when 3.75 moles of N₂ reacts with excess O₂.

When octane (C₈H₁₈) is burned in a very limited amount of oxygen, the result is the formation of C and H₂O. Calculate the mass (in g) of carbon formed from the partial burning of 1.00 L of octane. Note that the density of octane is 0.699 g/cm³. 

Iron is obtained from iron(III) oxide. In the following series of reactions, (step 1) hot air (O₂) reacts with coke (C) to produce CO₂ and heat up the blast furnace, (step 2) additional coke reduces CO₂ into CO, and (step 3) the very high temperature allows for CO to reduce Fe in Fe₂O₃.

(Step 1) C (s) + O₂ (g) → CO₂ (g)
(Step 2) CO₂ (g) + C (s) → 2 CO (g)
(Step 3) Fe₂O₃ (s) + 3 CO (g) → 2 Fe (l) + 3 CO₂ (g)

Write mole ratios to show the relationship between reaction components.

Lactose in dairy food is converted solely into lactic acid in a process called homolactic fermentation. 

C₁₂H₂₂O₁₁ + H₂O → 4 C₃H₆O₃ 

Given that the density of lactic acid is 1.21 g/cm³, calculate the volume (in quarts) of lactic acid that can be produced when 50.0 lb of lactose is fermented (1 lb = 454 g; 1 L = 1.057 quarts).

Silver fully dissolves in hot concentrated nitric acid which acts as an oxidizing agent to form the water-soluble silver nitrate and a brown gas. 

Ag (s) + 2 HNO₃ (aq) → AgNO₃ (aq) + NO₂ (g) + H₂O (l)

Determine whether 40.0 g of HNO₃ is enough to dissolve 30.0 g of Ag. 

Iron ore haematite (also spelled hematite) contains iron(III) oxide. Iron can be extracted from iron(III) oxide using a blast furnace according to the following reactions:

C (s) + O₂ (g) → CO₂ (g)

CO₂ (g) + C (s) → 2 CO (g)

Fe₂O₃ (s) + 3 CO (g) → 2 Fe (l) + 3 CO₂ (g)

Calculate the mass (in kg) of solid carbon required to obtain 100 kg of iron.

Iron can be extracted from iron(III) oxide using a blast furnace according to the following reactions:

C (s) + O₂ (g) → CO₂ (g)

CO₂ (g) + C (s) → 2 CO (g)

Fe₂O₃ (s) + 3 CO (g) → 2 Fe (l) + 3 CO₂ (g)

Calculate the number of moles of solid carbon required to obtain 2.0 moles of iron.

The diagram below represents the reaction: X₂ + 3 Y₂ → 2 XY₃.

Determine the number of moles of product that can form from (i) 2.0 mol X₂ and (ii) 2.0 mol Y₂. 

For the following unbalanced reaction: Na(s) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂(g). Calculate the amount (in moles) of sodium sulfate produced from 8.00 mol Na and 14.0 mol of H₂SO₄.

Consider the unbalanced reaction below:

Na(s) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂(g)

Calculate the amount of sodium (in moles) required to completely react with 6.25 moles of sulfuric acid.

Write the balanced reaction for the reaction of aluminum sulfide with water producing aluminum hydroxide and hydrogen sulfide.

If 10.5 g of aluminum sulfide was allowed to react calculate the mass of aluminum hydroxide produced. 

Calculate the mass of oxygen consumed in the combustion of 2.21 g of C₃H₈

The balanced reactions below shows the combustion of propane:

C₃H₈ (g) + 5 O₂ (g) → 3 CO₂ (g) + 4 H₂O (g) 

If 132.1 g of C₃H₈(g) is completely combusted, calculate the mass in grams of oxygen needed for this process.

Assuming that the reaction below goes to 100% completion, calculate the amount mass of each reactant needed to produce 360 L of water (MM = 18.013 g/mol). 

2 H₂ (g) + O₂ (g)  → 2 H₂O(l)

Consider the following reaction: 

3 NaBH₄ (aq) + 4 BF₃ → 3 NaBF₄ (aq) + 2 B₂H ₆

Calculate the number of hydrogen atoms in the B₂H₆ produced if 16.5 moles of NaBF₄ are also produced