Question

The number of oxygen atoms in $4.4g$ of $C{O}_2$ is approximately :

• A. $1.2\times {10}^{23}$
• B. $6\times {10}^{22}$
• C. $6\times {10}^{23}$
• D. $0.12\times {10}^{23}$

Answer 1

The correct option is A $1.2\times {10}^{23}$

Moles of $C{O}_2=\frac{4.4}{44}=0.1$ moles

$\therefore$ Number of molecules of $C{O}_2=0.1\times 6.022\times {10}^{23}$

=$6.022\times {10}^{22}$ molecules

But $1$ molecule of $C{O}_2$ contains $2$ oxygen atoms.

$\therefore$ Number of oxygen atoms=$2\times 6.022\times {10}^{22}$

=$12.044\times {10}^{22}$ atoms

=$1.2\times {10}^{23}$ atoms