Chapter 6, Problem 58A

Interpretation Introduction

Interpretation:

The mass of cobalt should be predicted which contains the same number of iron atoms.

Concept Introduction:

Molar mass is defined as an average mass of atoms present in the chemical formula. It is the sum of the atomic masses of all the atoms present in the chemical formula of any compound.

Answer to Problem 58A

The mass of the cobalt atom is 2.36 g

Explanation of Solution

Given information:

Mass of iron atom = 2.24 g

Atomic mass of iron per mole = 55.85 g

One mole of iron = 6.023 ×10²³ atoms

Calculation:

The calculation of number of iron atoms is shown below:

  $\begin{array}{c}\left(\text{2}\text{.24}\text{g}\text{Fe}\right)\left(\frac{\text{6}\text{.022}\text{×}{\text{10}}^{\text{23}}\text{Fe}\text{atoms}}{\text{55}\text{.85}\text{g}\text{Fe}}\right)\\ \text{=}\text{2}\text{.4156}\times {10}^{22}\text{Fe}\text{atoms}\end{array}$

No. of atoms of cobalt = 2.4156 × 10²² Co atoms

The calculation of mass of cobalt is shown below:

  $\begin{array}{c}\text{mass}\text{of}\text{cobalt}\text{=}\text{2}\text{.4156}\text{×}{\text{10}}^{\text{22}}\text{Co}\text{atoms}\text{×}\frac{\text{1}\text{mol}\text{Co}}{\text{6}\text{.023}\text{×}{\text{10}}^{\text{23}}\text{Co}\text{atoms}}\text{×}\frac{\text{58}\text{.93}\text{g}}{\text{1}\text{mol}\text{Co}}\\ \text{=}\text{2}\text{.36}\text{g}\end{array}$

Conclusion

Thus, the mass of the cobalt atom is 2.36 g.