Question

Complete the following reactions and give balanced equations:
CaOC{l_2} + NaI + HCl \to \\_\\_\\_\\_\\_\\_\\_\\_ + CaC{l_2} + {H_2}O + NaCl

Answer 1

The law of conservation of mass dictates that the quantity of each element should not change in a chemical reaction. Thus, each side of the chemical equation that is the product and the reactant side should represent the same quantity of a particular element. In a balanced equation charge on both sides of the reaction should also be conserved. Therefore, the same charge must be present on both sides of the reaction that is the same charge on the reactant side and the same charge on the product side.

Complete step by step solution:
In the reaction calcium hypochlorite gets reduced to calcium chloride. Sodium iodide, the iodine gets displaced by chlorine which we get from the molecule of hydrogen chloride. And the oxygen from calcium hypochlorite reacts with hydrogen to give water molecules. So, the iodine in sodium iodide gets displaced by chlorine to give a molecule of iodine only.
So, the complete reaction is as follows:
$CaOC{l_2} + NaI + HCl \to {I_2} + CaC{l_2} + {H_2}O + NaCl$
We can balance a chemical equation by changing the scalar number for each chemical compound or element present in the reaction irrespective of the compound or element being present on the reactant or on the product side. A simple reaction can be balanced by trial-and-error method just by inspecting.
So, now we will balance the above reaction by trial-and-error method as follows,
$CaOC{l_2} + NaI + HCl \to {I_2} + CaC{l_2} + {H_2}O + NaCl$ Here, we can see that on left side that is on the reactant side the number of calcium, oxygen, sodium and chlorine atoms are same as the number of calcium, oxygen, sodium and chlorine atoms on right that is on product side.
So, to balance the number of iodine and hydrogen atoms we first multiply sodium iodide by two and we multiply hydrogen chloride by two.
$CaOC{l_2} + 2NaI + HCl \to {I_2} + CaC{l_2} + {H_2}O + NaCl$
Now as we can see the number of iodine atoms are balanced but the number of sodium atoms have become two in reactant side. So, we multiply NaCl by two to make the number of atoms of sodium equal on both sides.
$CaOC{l_2} + 2NaI + HCl \to {I_2} + CaC{l_2} + {H_2}O + 2NaCl$
Now we can say that the equation is balanced as the quantity of chemical reactants is equal to the chemical compounds on the right side.

Note:
A chemical equation consists of the chemical formula of the reactants that is the formulas of compounds and symbols of elements. The chemical equation also requires the chemical formulas of the compound and elements of the products. The reactants and the products are separated by arrow and the individual compound or element is divided by a plus sign.