Chapter U4.76, Problem 8E

Interpretation Introduction

Interpretation: The given table needs to be completed.

Concept Introduction: The number of atoms in 1 mol of any substance is equal to $6.023\times {10}^{23}$ atoms. This is known as Avogadro’s number.

Explanation of Solution

Mass of 1 mol of carbon =12 g.

Number of moles of 24 g of C will be:

24 g C $\frac{24}{12}$ mol=2 mol.

Since, 1 mol C contains $6.02\times {10}^{23}$ atoms.

So, 2 mol C contains $\text{2}\times \text{6}\text{.02}\times {\text{10}}^{\text{23}}\text{atoms=1}\text{.20}\times {\text{10}}^{\text{24}}\text{atoms}$ .

Similarly,

Mass of 1 mol of Ca=40 g.

Number of moles in 40 g of Ca will be:

So, 40 g Ca $\frac{40}{40}$ mol=1 mol

Here,

1 mol Ca contains $=6.02\times {10}^{23}$ atoms.

Now,

20 g Ca $\frac{20}{40}$ mol=0.5 mol

Also,

0.5 mol Ca contains $\text{=0}\text{.5×6}{\text{.02×10}}^{\text{23}}\text{atoms=3}{\text{.01×10}}^{\text{23}}\text{atoms}$ .

The complete table will be as follows: