Chapter 3, Problem 3.117MP

Interpretation Introduction

(a)

Interpretation:

The percent composition of copper sulfide needs to be determined.

Concept introduction:

Amount of every element present in chemical compound is described by the concept which is known as Mass percentage composition. It is also called as percent by weight. It is abbreviated as $\text{w/w\%}$.

The mass percentage composition formula is given by the following expression:

$\text{\%mass =}\frac{\text{mass of elemnt in 1mole of compound}}{\text{molar mass of compound}}\text{×100\%}$

Interpretation Introduction

(b)

Interpretation:

The empirical formula needs to be determined.

Concept introduction:

Empirical formula is defined as the simplest ratio of atoms present in the compound.

Interpretation Introduction

(c)

Interpretation:

The copper ions per cubic centimeter needs to be determined.

Concept introduction:

The number of moles is related to mass and molar mass as follows:

$n=\frac{m}{M}$

In 1 mol of a substance there are $6.022\times {10}^{23}$ atoms.