Chapter 4, Problem 10SAQ

Interpretation Introduction

Interpretation:

The net ionic equation for the reaction when aqueous solutions of $\text{KOH}$ and ${\text{SrCl}}_{\text{2}}$ are mixed is to be identified.

Concept Introduction: Ionic equation is the balanced molecular equation in which the strong electrolytes are broken down to form their ions that are dissolved in an aqueous solution.

To identify: The net ionic equation for the reaction when aqueous solutions of $\text{KOH}$ and ${\text{SrCl}}_{\text{2}}$ are mixed.

Correct answer: The correct option is (b).

Reason for correct answer:

The molecular equation when aqueous solution of $\text{KOH}$ and ${\text{SrCl}}_{\text{2}}$ are mixed is,

$\text{2KOH}\left(aq\right)+{\text{SrCl}}_{\text{2}}\left(aq\right)\to \text{2KCl}\left(aq\right)+\text{Sr}{\left(\text{OH}\right)}_{\text{2}}\left(s\right)$

For the ionic equation, the molecular equation is written in the form of cations and anions of aqueous species separately,

${\text{2K}}^{\text{+}}\left(aq\right)+{\text{2OH}}^{-}\left(aq\right)+{\text{Sr}}^{\text{2+}}\left(aq\right)+{\text{2Cl}}^{-}\left(aq\right)\to {\text{2K}}^{\text{+}}\text{(}aq\text{)}+{\text{2Cl}}^{-}(aq\text{)}+{\text{Sr(OH)}}_{\text{2}}$

To get the ionic equation, the common ions are cancelled. The net ionic equation obtained for the given reaction is,

${\text{2OH}}^{-}(aq\text{)}+{\text{Sr}}^{\text{2+}}\text{(}aq\text{)}\to {\text{Sr(OH)}}_{\text{2}}(s)$

Reason for incorrect options:

The other three options (a), (c) and (d) are incorrect because they do not produce the cations and anions that match the net ionic equation.