# Worksheet: Reaction Masses

In this worksheet, we will practice calculating the masses of reactants and products using their formula masses, molar quantities, and ratios.

Q1:

Methane burns in oxygen according to the following equation:

What is the molar ratio of methane to oxygen?

• A
• B
• C
• D
• E

What is the molar ratio of methane to carbon dioxide?

• A
• B
• C
• D
• E

What is the molar ratio of oxygen to water?

• A
• B
• C
• D
• E

Q2:

Methane burns in oxygen according to the equation: The molar mass of methane is 16 g/mol, and the molar mass of molecular oxygen is 32 g/mol.

What is the ratio of the molar masses of methane and oxygen?

• A
• B
• C
• D
• E

What is the ratio of the mass of methane to the mass of oxygen in this reaction?

• A
• B
• C
• D
• E

What mass of oxygen is needed to for 1 g of methane to completely react?

Q3:

Sodium oxide reacts with hydrochloric acid to produce sodium chloride and water, according to the equation:

What is the molar ratio of to ?

• A
• B
• C
• D
• E

What is the molar mass of to two significant figures?

What mass of is required for 2.5 g of to completely react?

Q4:

Carbon tetrachloride can be synthesized by reacting chlorine with methane according to the equation: If 8.0 g of is produced, what mass of methane is consumed?

Q5:

Butane burns completely in oxygen according to the equation: If 44 g of carbon dioxide is produced in this reaction, how much oxygen is consumed?

Q6:

Magnesium and chlorine react together vigorously, producing magnesium chloride according to the following equation:

What is the relative atomic mass of magnesium, to the nearest gram per mole?

How many moles of magnesium atoms are there in 6.0 g of magnesium?

How many moles of magnesium chloride are produced when 6.0 g of magnesium reacts completely with chlorine?

What is the relative formula mass of magnesium chloride, to the nearest gram per mole?

How many grams of magnesium chloride are produced when 6.0 g of magnesium reacts completely with chlorine?

Q7:

Sulfur burns in oxygen to form sulfur dioxide. What is the mass of sulfur needed to produce 4 g of sulfur dioxide?

Q8:

To 3 significant figures, how much water can be produced from 4.800 g of oxygen and 0.5846 g of hydrogen?

Q9:

When aqueous solutions of sodium hydroxide and magnesium chloride are mixed, magnesium hydroxide precipitates. Calculate the mass of sodium hydroxide required to produce 16.0 g of magnesium hydroxide.

Q10:

Calculate the mass of gallium(III) oxide that can be prepared from 29.0 g of gallium.

Q11:

Calculate the mass of oxygen reacted in the complete combustion of 702 g of octane.

Q12:

The reaction of calcium hydroxide with phosphoric acid produces calcium phosphate and water as the only products. Calculate the mass of calcium hydroxide needed for 113 g of phosphoric acid to completely react.

Q13:

Iron(III) oxide and carbon monoxide react to form metallic iron and carbon dioxide as the only products.

Write a balanced chemical equation for this reaction, including state symbols.

• A
• B
• C
• D
• E

Calculate the mass of carbon monoxide needed for 25.13 g of iron(III) oxide to completely react, to three significant figures.

Calculate the mass of iron produced if 12.99 g of iron(III) oxide reacts with 6.750 g of carbon monoxide, to three significant figures.

Q14:

Aluminum and iodine react to form aluminum iodide as the only product.

Write a balanced chemical equation for this reaction, including state symbols.

• A
• B
• C
• D
• E

Calculate the number of moles of iodine needed for 0.429 mol of aluminum to completely react.

Calculate the mass of aluminum iodide produced if 3.50 g of iodine reacts with 0.350 g of aluminum.

Q15:

Silicon and nitrogen gas react to form silicon nitride as the only product.

Write a balanced chemical equation for this reaction, including state symbols.

• A
• B
• C
• D
• E

Calculate the mass of nitrogen needed for 8.080 g of silicon to completely react, to three significant figures.

Calculate the mass of silicon nitride produced if 53.20 g of silicon reacts with 36.37 g of nitrogen, to three significant figures.

Q16:

How many grams of oxygen gas are necessary to react completely with atoms of magnesium to yield magnesium oxide?

• A g
• B g
• C0.156 g
• D g
• E g

Q17:

Chlorine gas is produced industrially by the electrolysis of molten or aqueous sodium chloride. What mass of chlorine can be produced from 3.00 kg of sodium chloride, to 3 significant figures?

Q18:

What mass of hydrogen is produced when 10.01 g of calcium reacts completely with water?

Q19:

The complete combustion of acetylene produced 13.0 kg of water.

Calculate the number of moles of acetylene reacted.

Calculate the mass of oxygen reacted.

Q20:

Oxygen and mercury were produced by thermally decomposing 3.95 g of mercury(II) oxide.

Calculate the number of moles of mercury(II) oxide reacted.

Calculate the mass of oxygen gas produced.

Q21:

1,2-Dibromoethane () was produced by reacting 12.85 g of ethane with an excess of bromine.

Calculate the number of moles of 1,2-dibromoethane produced, to 3 significant figures.

Calculate the mass of bromine reacted.

Q22:

Calcium hydroxide and ammonium sulfate react to form ammonia, calcium sulfate, and water as the only products. Calculate, to 2 significant figures, the number of molecules of ammonia produced if 529 g of ammonium sulfate reacts with 385 g of calcium hydroxide.

• A
• B
• C
• D
• E

Q23:

A sample of magnesium required 5.00 g of hydrogen chloride gas to completely react.

Calculate the number of moles of magnesium reacted.

Calculate the mass of magnesium chloride produced.

Q24:

A sample of ethene reacted with water to produce 9.55 g of ethanol.

Calculate the number of moles of ethene reacted.

Calculate the mass of water reacted.

Q25:

To 3 significant figures, how many molecules of water are produced by the complete combustion of 33.08 g of propane?

• A
• B
• C
• D
• E