What is a chemical equation? Explain with the help of an example. (b) Giving examples, state the difference between balanced and unbalanced chemical equations. (c) Balance the following chemical equations: (i) NH3 → N2 + H2 (ii) C +CO2→ CO

• (a) Solutions:
  • Chemical equations are the symbolic representation of chemical reactions in which the reactants and products are expressed in terms of chemical formulae. Reactant entities are given on the left side and product entities are given on the right side of a chemical equation

Example: Zn + H2SO4→ZnSO4 + H2

• A balanced chemical equation is always energy and mass conservative whereas unbalanced chemical equation is neither energy nor mass conservative. A chemical equation can be written by balancing total number of atoms of each element in reactants and products while in unbalanced chemical equations the total number of atoms of each element in reactants and products are not equal

Example: KClO3→KCl + 3O2 Unbalanced equation 2KCl03→2KCl + 3O2 Balanced equation

• (i) 2NH3 → N2 + 3H2

(ii) C +CO2→ 2CO