GCSE Chemistry - What is a Limiting Reactant? Limiting/Excess Reactants Explained #27

The video tutorial explains the concept of limiting reactants in chemical reactions, using the example of hydrochloric acid reacting with calcium carbonate. It highlights the importance of identifying the limiting reactant to determine the amount of product formed. The tutorial also covers how to calculate the mass of a product, such as sodium oxide, by using stoichiometry and balanced chemical equations.

What indicates that calcium carbonate is the limiting reactant in the reaction with hydrochloric acid?

• The temperature of the solution increases.

• The calcium carbonate completely disappears.

• The solution changes color.

• The hydrochloric acid evaporates.

Why is it important to identify the limiting reactant in a chemical reaction?

• It alters the speed of the reaction.

• It determines the color of the product.

• It affects the amount of product formed.

• It changes the temperature of the reaction.

In the example of burning sodium in air, which reactant is in excess?

• Sodium

• Oxygen

• Water

• Sodium oxide

How do you calculate the number of moles of a substance?

• Volume divided by mass

• Mass divided by molar mass

• Mass divided by volume

• Volume divided by molar mass

What is the molar mass of sodium oxide (Na2O)?

• 62 g/mol

• 94 g/mol

• 46 g/mol

• 78 g/mol