Question

Write balanced equations for the following reactions
(i)Chlorine gas and potassium bromide react to produce potassium chloride and bromine.
(ii) Iron (II) oxide when heated in hydrogen produces iron and water.
(iii) A solution of mercury (I) nitrate reacts with a solution of potassium iodide to produce a bright orange mercury (I) iodide precipitate and a solution of potassium nitrate.

Answer 1

Hint:A balanced chemical equation contains the same amount of reactants as well as the products. It tells us the exact number of quantities involved in a chemical reaction, which is useful for practical and industrial purposes.

Complete step-by-step answer:We have been given to balance three cases of reactions. A balanced chemical equation is a compilation of the equal amount of atoms on the reactant side, as well as on the product side. Since we are given the reactant and products, we will write them, and compare their amount, then add the relevant values of atoms on both the sides.
(i)For the reaction of chlorine gas and potassium bromide, potassium chloride and bromine are produced, these can be written as,
\[C{{l}_{2}}+KBr\to KCl+B{{r}_{2}}\]
Since, we have 2 chlorine and 2 bromine, so we will write 2 in front of potassium bromide and potassium chloride as,
\[C{{l}_{2}}+2KBr\to 2KCl+B{{r}_{2}}\], thus this equation is balanced.
(ii) We have iron (II) oxide that is heated in hydrogen to obtain iron and water as,
$FeO+{{H}_{2}}\xrightarrow{\Delta }Fe+{{H}_{2}}O$ , as the amount of reactants is equal to products, this equation is balanced.
(iii) We have solution of mercury (I) nitrate that reacts with potassium iodide, to produce mercury (I) iodide precipitate and potassium nitrate solution, this is written as,
$HgN{{O}_{3}}+KI\to KN{{O}_{3}}+HgI(s)\downarrow $, here also since the amount of reactants is equal to products, this equation is balanced.
Hence, all the equations have been balanced.

Note:For balancing of complex equations where disproportionation occurs, which is oxidation and reduction simultaneously occurring, methods like oxidation number method, and half reaction methods are used to balance the chemical equations.