IGCSE Chemistry Year 10 Balancing Reactions Quiz

What is the law of conservation of mass in chemical reactions?

• Matter can be transformed into energy in chemical reactions

• Matter is destroyed in chemical reactions

• Matter is constantly increasing in chemical reactions

• Matter is neither created nor destroyed, it is only transformed from one form to another.

Why is it important to balance chemical equations?

• To make the equation look more complicated

• To confuse students

• To ensure that the law of conservation of mass is obeyed.

• To waste time in chemistry class

What are reactants and products in chemical reactions?

• Reactants are the substances present at the beginning of a chemical reaction, and products are the substances formed as a result of the reaction.

• Reactants and products are interchangeable terms in chemical reactions.

• Reactants are the substances formed as a result of the reaction, and products are the substances present at the beginning of a chemical reaction.

• Reactants and products have no specific roles in chemical reactions.

Explain the concept of chemical reaction coefficients.

• They are used to measure the temperature change in a chemical reaction

• They indicate the speed of a chemical reaction

• They are related to the color change in a chemical reaction

• They represent the number of moles of each reactant and product involved in a balanced chemical equation.

Balance the chemical equation: H2 + O2 → H2O

• H2 + O2 → H2O2

• H2O + O2 → H2O2

• 2H2 + O2 → 2H2O

• 2H2 + 2O2 → 2H2O

Balance the chemical equation: Fe + O2 → Fe2O3

• 3Fe + 2O2 → Fe2O3

• 2Fe + 3O2 → Fe2O3

• 4Fe + 3O2 → 2Fe2O3

• Fe + 2O2 → Fe2O3

Balance the chemical equation: N2 + H2 → NH3

• N2 + 3H2 → 2NH3

• N2 + 4H2 → 3NH3

• N2 + 2H2 → NH3

• N2 + H2 → NH2

Balance the chemical equation: C3H8 + O2 → CO2 + H2O

• C3H8 + 4O2 → 3CO2 + 2H2O

• C3H8 + 5O2 → 3CO2 + 4H2O

• C3H8 + O2 → 2CO2 + 2H2O

• C3H8 + 2O2 → 3CO2 + 4H2O

What happens if a chemical equation is not balanced?

• The reaction will be more accurate

• The reaction will proceed faster

• The reaction may not proceed as expected or may not occur at all.

• The reaction will produce more products

Explain the process of balancing a chemical equation using an example.

• Example: H2O -> H2 + O2

• Example: 2H2 + O2 -> 2H2O

• Example: H2 + O2 -> H2O2

• Example: 2H2O -> 2H2 + O2