Science
What is a balanced chemical equation? Why should chemical equations be balanced?
Answer
A balanced equation is one in which the number of atoms of each element of the reactant is equal to the number of atoms of each element of the products.
An equation must be balanced in order to comply with the "Law of Conservation of Mass", which states that mass is neither created nor destroyed in the course of a chemical reaction. An unbalanced equation would imply that atoms have been created or destroyed.
Related Questions
Fe2O3 + 2Al ⟶ Al2O3 + 2Fe
The above reaction is an example of a
- combination reaction.
- double displacement reaction.
- decomposition reaction.
- displacement reaction.
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
- Hydrogen gas and iron chloride are produced.
- Chlorine gas and iron hydroxide are produced.
- No reaction takes place.
- Iron salt and water are produced.
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
Balance the following chemical equations.
(a) HNO3 + Ca(OH)2 ⟶ Ca(NO3)2 + H2O
(b) NaOH + H2SO4 ⟶ Na2SO4 + H2O
(c) NaCl + AgNO3 (aq) ⟶ AgCl + NaNO3
(d) BaCl2 + H2SO4 ⟶ BaSO4 + HCl