Chapter 16, Problem 31QP

Interpretation Introduction

Interpretation:

The mass of $\text{NaOH}$ in grams from the given pH and the volume of its solution is to be determined.

Concept introduction:

Number of moles $\left(n\right)$ of any substance is defined as the ratio of its given mass $\left(m\right)$ to its molecular mass $\left(\text{MM}\right)$.

$n=\frac{m}{\text{MM}}$ …… (1)

Molarity $\left(M\right)$ is defined as the concentration of a solution in terms of the number of moles $\left(n\right)$ of solute in one-liter solution. Mathematically, it is expressed as:

$M=\frac{n}{V}$ …… (2)

Here, $V$ is the volume of the solution in liters. Molarity is also defined as $\text{mol/L}$.

A strong base is an electrolyte that gets completely dissociated when dissolved in water to produce hydroxide ions and its conjugate acid.

$\text{BOH}\left(aq\right)\to {\text{B}}^{\text{+}}\left(aq\right)+{\text{OH}}^{-}\left(aq\right)$

pOH is the measure of basicity of a solution that depends on the concentration of hydroxide ions and the temperature of the solution.

The formula to calculate the hydroxide ion concentration is:

$\left[{\text{OH}}^{-}\right]={10}^{-\text{pOH}}$ …… (3)

The relationship between pH and pOH is:

$\text{pH}+\text{pOH}=14$ …… (4)

The conversion factor to convert $\text{mL to L}$ is:

$\frac{1\text{ L}}{1000\text{ mL}}$