Question

How many $\mathrm{Ag}$ atoms are there in 0.0001 grams of $\mathrm{Ag}$? The molar mass of $\mathrm{Ag}$ is 108 grams per mole.

Answer 1

Step 1: Calculate the number of moles.

• number of moles $=\frac{\mathrm{Given}\mathrm{mass}}{Molarmass}$$=\frac{0.0001}{108}mol$

Step 2: Calculate the number of atoms

• Since 1 mol of a substance contains ${\mathrm{N}}_{\mathrm{A}}$ atoms. i.e. $6.023\times {10}^{23}$ atoms.
• Number of atoms in $\frac{0.0001}{108}$ mol will be $=\frac{0.0001}{108}\times 6.023\times {10}^{23}=5.57\times {10}^{23}$atoms

Hence, there are total $5.57\times {10}^{17}$ atoms of $\mathrm{Ag}$.