PRACTICE: Limiting Reactants

What is the balanced equation for the reaction between H2 and F2?

• H2 + F2 → HF

• H2 + F2 → H2F2

• H2 + F2 → 2HF

• H2 + F2 → H2 + F2

What is a limiting reactant?

• The reactant that is present in excess in a chemical reaction.

• The substance that is completely consumed in a chemical reaction, limiting the amount of product that can be formed.

• The reactant that determines the rate of the reaction.

• The product that is formed in the largest quantity in a chemical reaction.

How do you calculate the amount of product formed from a limiting reactant?

• Use the mole ratio from the balanced equation to convert moles of the limiting reactant to moles of the product.

• Multiply the moles of the limiting reactant by its molar mass.

• Add the moles of all reactants to find the total product formed.

• Use the volume of the limiting reactant to determine the product amount.

What is Avogadro's number?

• 6.022 x 10^23

• 3.14159 x 10^22

• 1.602 x 10^-19

• 9.109 x 10^-31

What is the molar mass of HF?

• 18 g/mol

• 20 g/mol

• 22 g/mol

• 25 g/mol

What is the product formed when H2 reacts with F2?

• Hydrogen fluoride (HF)

• Hydrogen bromide (HBr)

• Fluorine gas (F2)

• Hydrogen chloride (HCl)

What happens to the excess reactant in a chemical reaction?

• The excess reactant is completely consumed along with the limiting reactant.

• The excess reactant remains unreacted after the limiting reactant is completely consumed.

• The excess reactant is converted into a product during the reaction.

• The excess reactant increases the rate of the reaction significantly.

What is the mole ratio?

• The mole ratio is the ratio of moles of one substance to the moles of another substance in a balanced chemical equation.

• The mole ratio is the total number of moles in a solution.

• The mole ratio is the ratio of mass of one substance to the mass of another substance.

• The mole ratio is the number of molecules in a gas at standard temperature and pressure.

What is the significance of the limiting reactant in a chemical reaction?

• It increases the rate of the reaction.

• It determines the maximum amount of product that can be formed in a reaction.

• It has no effect on the reaction outcome.

• It is the reactant that is present in excess.

If you have 2 moles of H2 and 1 mole of F2, which is the limiting reactant?

• H2 is the limiting reactant because it will be consumed first based on the stoichiometry of the reaction.

• F2 is the limiting reactant because it is present in a smaller amount.

• Both H2 and F2 are limiting reactants as they will react completely.

• There is no limiting reactant in this reaction.