Question

Define chemical equation. Give one example.

Answer 1

• A chemical equation is a symbolic representation of a chemical reaction in the form of symbols and formulae.
• A chemical equation gives us a lot of useful information about the chemical changes occurring in a chemical reaction like the number of reactants and products, change of state, change of energy, etc.
• Example: When Calcium oxide$\left(\mathrm{CaO}\right)$ reacts with water$\left({\mathrm{H}}_2\mathrm{O}\right)$ Calcium hydroxide$\left[\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$ is formed as a product.

$$\begin{gathered} \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+\mathrm{Heat} \\ (\mathrm{Calcium}\mathrm{oxide})\left(\mathrm{Water}\right)(\mathrm{Calcium}\mathrm{hydroxide}) \end{gathered}$$