1.4 - Balancing Chemical Equations

Question 1

What are mixed together during a chemical reaction to form products?

Answer 1

Reactants

Reactants are substances that undergo a chemical change in a reaction.

Question 2

Balance the following chemical equation: N2 + ______ H2 ➔ ______ NH3

Answer 2

first gap = 3

second gap =2

The balanced equation is N2 + 3H2 ➔ 2NH3.

Question 3

When representing oxygen in a symbol equation, should you write ‘O’ or ‘O2’?

Answer 3

O2

Oxygen exists as a diatomic molecule in nature, hence the correct representation is O2.

Question 4

Balance the following chemical equation: CH4 + ______ O2 ➔ CO2 + ______ H2O

Answer 4

2, 2

The balanced equation is CH4 + 2O2 ➔ CO2 + 2H2O.

Question 5

Choose the correct balanced equation for the reaction of iron and chlorine: ?Fe + ?Cl2 ➔ ?FeCl3

Answer 5

2Fe + 3Cl2 ➔ 2FeCl3

This equation is balanced as it maintains the same number of each type of atom on both sides.

Question 6

True or False: When balancing symbol equations, you can use fractions in front of chemicals.

Answer 6

False

Only whole numbers should be used in front of chemicals when balancing equations.

Question 7

Choose the correct balanced equation for the reaction of sodium with water: Na + H2O ➔ 2NaOH + H2

Answer 7

2Na + 2H2O ➔ 2NaOH + H2

This equation is balanced as it complies with the law of conservation of mass.