Question

Balance and complete the following equations :

${\mathrm{P}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to$

Answer 1

Chemical equation :

• The method of representing chemical reaction in terms of symbols and formulae of the substances involved in it is called chemical equation.
• For example, $$\begin{gathered} {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to {\mathrm{H}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right) \\ \mathrm{Water}\mathrm{Carbon}\mathrm{dioxide}\mathrm{Carbonic}\mathrm{acid} \end{gathered}$$
• In the above example, the substances such as hydrogen, oxygen and carbon are represented by their respective symbols, hence, it is a chemical equation.

Balanced chemical equation :

• The chemical equation in which the number of atoms of each element is equal to both sides of the chemical equation is called balanced chemical equation.
• In the above example, the number of atoms of each element ( hydrogen, oxygen, carbon) are equal to both sides of the chemical equation, hence , it is a balanced chemical equation.
• Reactant side Product side
• Element No. of atom/s Element No. of atom/s
• Hydrogen 2 Hydrogen 2
• Oxygen 3 Oxygen 3
• Carbon 1 Carbon 1

Conclusion :

• When di phosphorus pentoxide reacts with water , phosphoric acid is formed
• $$\begin{gathered} {\mathrm{P}}_2{\mathrm{O}}_5\left(\mathrm{s}\right)+3{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{H}}_3{\mathrm{PO}}_4 \\ \mathrm{Diphosphorus}\mathrm{Water}\mathrm{Phosphoric} \\ \mathrm{pentoxide}\mathrm{acid} \end{gathered}$$
• Reactant side Product side
• Element No. of atom/s Element No. of atom/s
• Phosphorus $2$ Phosphorus $2$
• Oxygen $5+3=8$ Oxygen $2\times 4=8$
• Hydrogen $3\times 2=6$ Hydrogen $2\times 3=6$