Question

The atomic mass of $\mathbf{CI}$is 35.45 amu, and the atomic mass of$\mathbf{AI}$is 26.98 amu. What are the masses in grams of 3 mol ofrole="math" localid="1657099526671" $\mathbf{AI}$atoms and of 2 mol ofrole="math" localid="1657099457858" $\mathbf{CI}$atoms?

Short answer

The mass of$\mathbf{AI}$ is80.94 grams.

The mass of$\mathbf{CI}$ is70.9 grams.

Step-by-step solution

Relation between mass and number of moles

The number of moles is calculated by the mass and Molar mass. The relationship between the number of moles, mass, and molar mass is given below.

$\mathbf{Number}\mathbf{}\mathbf{of}\mathbf{}\mathbf{moles}\mathbf{=}\frac{\mathbf{mass}}{\mathbf{Molarmass}}$

Calculate the mass of AI

The molar mass of $\mathbf{AI}$= 26.98 amu = 26.98 g/mol

The number of moles of $\mathbf{AI}$= 3 mol

Thus, the mass of $\mathbf{AI}$is:

$$\begin{gathered} \mathrm{mass}\mathrm{of}\mathrm{Al}=\mathrm{moles}\mathrm{of}\mathrm{Al}\times \mathrm{Molarmass}\mathrm{of}\mathrm{Al} \\ =3\mathrm{mol}\times 26.98\mathrm{g}/\mathrm{mol} \\ =80.94\mathrm{g} \end{gathered}$$

Calculate the mass of CI

The molar mass of = 35.45 amu = 35.45 g/mol

The number of moles of = 2 mol

Thus, the mass of is:

$$\begin{gathered} \mathrm{mass}\mathrm{of}\mathrm{Cl}=\mathrm{moles}\mathrm{of}\mathrm{Cl}\times \mathrm{Molarmass}\mathrm{of}\mathrm{Cl} \\ =2\mathrm{mol}\times 35.45\mathrm{g}/\mathrm{mol} \\ =70.90"\hspace{0.33em}\mathrm{g}) \end{gathered}$$