Chapter 19, Problem 19.134MP

(a)

Interpretation Introduction

Interpretation:

The mass percent of $N{H}_4{\text{NO}}_3$ and ${\left(N{H}_4\right)}_{2}HP{O}_4$ in a mixture which shows the mass percent of nitrogen to be $33.81\%$ has to be determined.

Concept introduction:

Molecular weight:

The sum of the atomic weight of each constituent element multiplied by the number of atoms of that element is known as molecular weight of the compound.

It can be determined by using the molecular formula.

Mass percent:

It represents the mass of the constituent element in grams per exactly $100g$ of compound.

$mass\%=\frac{massofelementincompound}{massofcompound}\times 100\%$

(b)

Interpretation Introduction

Interpretation:

A $0.965g$ sample of the mixture was dissolved in enough water to make $50.0mL$ of solution the $pH$ of this solution should be determined.

Concept introduction:

$pH$ and $pOH$ can be calculated using the below mentioned equations;

$\begin{array}{c}\text{pH=}\text{-log}\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]\\ \text{pOH}\text{=}\text{-log}\left[{\text{OH}}^{\text{-}}\right]\end{array}$

The $pHandpOH$ of a water solution at ${25}^{0}C$ are related by the following equation,

$pH+pOH=14$

Molarity is the amount of moles of a compound dissolved in an amount of solvent (in liters)

$Molarity\left(M\right)=\frac{Molesofsolute}{Litersofsolution}$