Chapter 14, Problem 14.68SP

(a)

Interpretation Introduction

Interpretation:

Among the given indicators which would be most appropriate to detect a $\text{pH}$ change from $\text{7 to 5}$ has to be identified.

Concept Information:

The approximate $\text{pH}$ of the solution can be measured by using acid-base indicator, a substances changes their colour in particular range of $\text{pH}$. Indicator ($\text{HIn}$) show $\text{pH}$ dependent colour changes because of weak acid and has various colours in their acid solution and forms conjugate base $\left({\text{In}}^{\text{-}}\right)$

$\begin{array}{l}{\text{HIn}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\rightleftharpoons }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{\left(\text{aq}\right)}{\text{+In}}^{\text{-}}{}_{\left(\text{aq}\right)}\\ \text{Colour A}\text{Colour A}\end{array}$

(b)

Interpretation Introduction

Interpretation:

Among the given indicators which would be most appropriate to detect a $\text{pH}$ change from $\text{8 to 10}$ has to be identified.

Concept Information:

The approximate $\text{pH}$ of the solution can be measured by using acid-base indicator, a substances changes their colour in particular range of $\text{pH}$.  Indicator ($\text{HIn}$) show $\text{pH}$ dependent colour changes because of weak acid and has various colours in their acid solution and forms conjugate base $\left({\text{In}}^{\text{-}}\right)$

$\begin{array}{l}{\text{HIn}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\rightleftharpoons }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{\left(\text{aq}\right)}{\text{+In}}^{\text{-}}{}_{\left(\text{aq}\right)}\\ \text{Colour A}\text{Colour A}\end{array}$

(c)

Interpretation Introduction

Interpretation:

Among the given indicators which would be most appropriate to detect a $\text{pH}$ change from $\text{3 to 5}$ has to be identified.

Concept Information:

The approximate $\text{pH}$ of the solution can be measured by using acid-base indicator, a substances changes their colour in particular range of $\text{pH}$.  Indicator ($\text{HIn}$) show $\text{pH}$ dependent colour changes because of weak acid and has various colours in their acid solution and forms conjugate base $\left({\text{In}}^{\text{-}}\right)$

$\begin{array}{l}{\text{HIn}}_{\left(\text{aq}\right)}{\text{+H}}_{\text{2}}{\text{O}}_{\left(\text{l}\right)}\stackrel{}{\rightleftharpoons }{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{\left(\text{aq}\right)}{\text{+In}}^{\text{-}}{}_{\left(\text{aq}\right)}\\ \text{Colour A}\text{Colour A}\end{array}$