Question

The molar mass of carbon dioxide is 44 g. The number of molecules present in 176 g of carbon dioxide is $a\times {10}^{24}$. Find the value of a.

• A. 2.41

Answer 1

The correct option is A 2.41

Given, mass of carbon dioxide = 156 g
Molar mass of ${\text{CO}}_2$ = 44 g
Avogadro's number = $6.022\times {10}^{23}$

Number of moles of carbon dioxide
= $\frac{\text{Given mass in gm}}{\text{Molar mass in gm}}$ = $\frac{156}{44}$ = 4

Number of molecules of carbon dioxide
= $\text{Number of moles}\times \text{Avogadro's number}$

$\therefore$ Number of molecules of carbon dioxide
= $4\times 6.022\times {10}^{23}$
= $2.41\times {10}^{24}$
= $a\times {10}^{24}$
$\therefore$ The value of a is 2.41