Question

Balance the equation: ${\mathrm{CaCO}}_3+\mathrm{HCl}\to {\mathrm{CaCl}}_2+{\mathrm{H}}_2\mathrm{O}+{\mathrm{CO}}_2$

Answer 1

1. Calcium carbonate is not very soluble in water.
2. This is an acid-base reaction (neutralization): ${\mathrm{CaCO}}_3$ is a base, and $\mathrm{HCl}$ an acid.
3. $\mathrm{Calcium}\mathrm{Carbonate}+\mathrm{Hydrogen}\mathrm{Chloride}\to \mathrm{Calcium}\mathrm{Chloride}+\mathrm{Water}+\mathrm{Carbon}\mathrm{Dioxide}$.

Balanced chemical equation:

The representation of a chemical reaction in the form of substances is known as a chemical equation.

1. The equation in which the number of atoms of all the molecules is equal on both sides of the equation is known as a balanced chemical equation.
2. The Law of conservation of mass governs the balancing of a chemical equation.
3. According to this law, mass can neither be created nor be destroyed in a chemical reaction, and obeying this law total mass of the elements or molecules present on the reactant side should be equal to the total mass of elements or molecules present on the product side.
4. If the chemical equation is not balanced law of conservation is not applicable.

Step 1: Balancing HCl

1. The given chemical equation: ${\mathrm{CaCO}}_3+\mathrm{HCl}\to {\mathrm{CaCl}}_2+{\mathrm{H}}_2\mathrm{O}+{\mathrm{CO}}_2$
2. We balance the equation by adding 2 moles $\mathrm{HCl}$ on LHS for 1 mole of ${\mathrm{H}}_2\mathrm{O}$ on RHS.
3. Balanced chemical equation: ${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{CaCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$
4. Hence, the above-mentioned is a completely balanced chemical equation.