Question

Strength of an acid solution or a basic solution can be determined by knowing the hydrogen ion concentrations in them, using a $pH$ scale.
(i) Neutral solution has $pH$ 7.
(ii) Acidic solution has $pH$ less than 7.
(iii) Basic solution has $pH$ more than 7.
The $pH$ of a solution is inversely proportional to hydrogen $\left(H^{+}\right)$ ion concentration in it.

Five students Ankit, Nitin, Deepika, Gunjan and Pooja were given test tubes having solutions with $pH$ 1.2, 13.5, 10.0, 7.4 and 2.2 respectively. The correct order of decreasing $O{H}^{-}$ ions concentration in these solutions is:

• A. Ankit > Pooja > Gunjan > Deepika > Nitin
• B. Nitin > Gunjan > Ankit > Pooja > Deepika
• C. Deepika > Gunjan > Pooja > Nitin > Ankit
• D. Nitin > Deepika > Gunjan > Pooja > Ankit

Answer 1

The correct option is D Nitin > Deepika > Gunjan > Pooja > Ankit

As we know,
$pH=-log\left[H^{+}\right]$ and
$pOH=14-pH$
So order is:
Nitin > Deepika > Gunjan > Pooja > Ankit