Question

Express mass of $6.022\times {10}^{23}$ molecules of ${\mathrm{CO}}_2$ in grams.

Answer 1

Step 1: Formula used

A mole is the quantity of any material which contains one Avogadro number ($6.022\times {10}^{23}$) of atoms, molecules, or ions.

$1\mathrm{mol}$ of ${\mathrm{CO}}_2$$=6.022\times {10}^{23}$ molecules of ${\mathrm{CO}}_2$

$\text{Number of moles=}\frac{\mathrm{Given}\mathrm{mass}}{\mathrm{Molar}\mathrm{mass}}$

Step 2: Expressing the mass in grams

The molar mass of ${\mathrm{CO}}_2$

$$\begin{gathered} =\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{C}+2\times \mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{O} \\ =12+2\times 16 \\ =12+32 \\ =44\mathrm{u} \end{gathered}$$

$\therefore$Mass of ${\mathrm{CO}}_2$ in terms of grams is

$$\begin{gathered} =1\mathrm{mol}\times 44\mathrm{u} \\ =44\mathrm{grams} \end{gathered}$$

Therefore, The mass of $6.022\times {10}^{23}$ molecules of ${\mathrm{CO}}_2$ is $44$ grams.