Chapter 7.3, Problem 1RQ

a)

Interpretation Introduction

Interpretation :

Chemical equation must be written and balanced when gaseous chlorine reacts with aqueous solution of potassium bromide to produce liquid bromine and aqueous solution of potassium chloride.

Concept Introduction :

Chlorine can displace bro mine from its salt is reactivity of chlorine is more than that of bromine.

Answer to Problem 1RQ

Unbalanced and balanced chemical equations are given below.

  $\begin{array}{l}{\text{Cl}}_{\text{2}}\text{(g)+KBr(aq)}\to {\text{Br}}_{\text{2}}\text{(l)+KCl(aq)}.\\ {\text{Cl}}_{\text{2}}\text{(g)+2KBr(aq)}\to {\text{Br}}_{\text{2}}\text{(l)+2KCl(aq)}\end{array}$

Explanation of Solution

From the reaction it can be seen that to balance the 2 Cl atoms 2 moles of KCl is required in product side. Then to balance 2 K atoms in product side 2 moles of KBr is required in reactant side. Number of Cl, K and Br atoms are equal in both the sides of the balanced equation.

b)

Interpretation Introduction

Interpretation :

Chemical equation must be written and balanced when solid aluminium reacts with solid iodine to produce solid aluminium iodide.

Concept Introduction :

Aluminium is an electropositive metal which can combine with iodine to produce corresponding iodide compound.

Answer to Problem 1RQ

Unbalanced and balanced chemical equations are given below.

  $\begin{array}{l}{\text{Al(s)+I}}_{\text{2}}\text{(s)}\to {\text{AlI}}_{\text{3}}\text{(s)}\text{.}\\ {\text{2Al(s)+3I}}_{\text{2}}\text{(s)}\to {\text{2AlI}}_{\text{3}}\text{(s)}\text{.}\end{array}$

Explanation of Solution

From the reaction it can be seen that to balance the 2 Al atoms 2 moles of AlI₃ is required in product side. Then to balance 6 I atoms in product side 3 moles of I₂ is required in reactant side. Number of Al and I are equal in both the sides of the balanced equation.