Chapter 10, Problem 98A

Interpretation Introduction

Interpretation:

The number of particles of gold atoms present in the bracelet should be calculated.

Concept introduction:

Number of moles of a compound is defined as the ratio of given mass of the compound to the molar or molecular mass of the compound.

The mathematical expression is given by:

Number of moles = $\frac{\text{given mass of the compound}}{\text{molar mass of the compound}}$

The one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Answer to Problem 98A

The number of particles of gold atoms present in the bracelet = $9.033\times {10}^{22}\text{ atoms}$.

Explanation of Solution

A bracelet contains 75 % gold.

Given number of moles of metal atoms = 0.200 mole

Thus, number of moles of gold in 75 % gold $=0.200\text{ mole}\times \frac{75}{100}$

= $0.15\text{ mole}$

Since, one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Thus, number of gold particles = $0.15\text{ mole}\times \text{6}\text{.022}\times {\text{10}}^{23}\frac{\text{atoms}}{\text{mole}}$

= $9.033\times {10}^{22}\text{ atoms}$