Question

Write balanced chemical equations for the following chemical reactions.

(a) Hydrogen+ Chlorine → Hydrogen Chloride

(b) Lead+ Copper Chloride → Lead Chloride + Copper

(c) Zinc Oxide + Carbon → Zinc + Carbon Monoxide

Answer 1

Balanced chemical equations

Chemical equations are used to represent the chemical changes occurring in a system. A chemical equation is considered balanced if it obeys the law of conservation of mass. This means that the number of atoms of each element in the reactant side will be equal that in the product side. Hit and trial method is used to balance a chemical equation in which coefficients are added to reactants and products such that the number of atoms becomes equal on both sides. The coefficients of reactants and products in a balanced chemical equation are called stoichiometric coefficients and gives their relative amounts.

(a) In this reaction Hydrogen (H₂) reacts with Chlorine (Cl₂) to form Hydrogen Chloride (HCl). This is an example for a combination reaction in which two or more reactants react to form a single product. All the reactants and product in this reaction are in gaseous state.

The balanced chemical equation for the reaction is:

$H_2\left(g\right)+C{l}_2\left(g\right)\to 2HCl\left(g\right)$

(Hydrogen) (Chlorine) (Hydrochloric acid)

(b) In this reaction, Lead (Pb) reacts with Copper chloride (CuSO₄) solution to form Lead chloride (PbSO₄) and Copper (Cu). This is an example for a single displacement reaction in which more reactive Lead displaced Copper from its salt solution.

The balanced equation for the reaction is:

$Pb\left(s\right)+CuC{l}_2\left(aq\right)\to PbC{l}_2\left(aq\right)+Cu\left(s\right)$

(Lead) (Copper (Lead (Copper)

chloride) chloride)

(c) In this reaction, Zinc oxide (ZnO) reacts with elemental Carbon (C) to form Zinc metal (Zn) and Carbon monoxide (CO). It is an example for a redox reaction in which Zinc oxide is reduced and Carbon is oxidized.

The balanced equation for the reaction is:

$ZnO\left(s\right)+C\left(s\right)\to Zn\left(s\right)+CO\left(g\right)$

(Zinc (Carbon) (Zinc) (Carbon

oxide) monoxide)