Question

Atomic mass of $\mathrm{Gold}\left(\mathrm{Au}\right)$ is $197$u. How many moles of $\mathrm{Gold}$ are present in an Ornament Containing $88.65\mathrm{g}$ of $\mathrm{Gold}$.

Answer 1

Given - Atomic mass of $\mathrm{Gold}\left(\mathrm{Au}\right)$ is $197$u.

$\mathrm{Moles}\mathrm{of}\mathrm{an}\mathrm{atom}=\frac{\mathrm{Mass}\mathrm{of}\mathrm{an}\mathrm{Element}\mathrm{in}\mathrm{grams}}{\mathrm{Gram}\mathrm{Atomic}\mathrm{mass}}$

Gram atomic mass of $\mathrm{Gold}\left(\mathrm{Au}\right)$ is $197\mathrm{g}$.

Thus, Substituting the Given values in above Formula

$\mathrm{Moles}\mathrm{of}\mathrm{Gold}=\frac{88.65}{197}$

$\mathrm{Moles}\mathrm{of}\mathrm{Gold}=0.45\mathrm{Mole}$

Hence, $0.45$ moles of $\mathrm{Gold}$ are present in an Ornament Containing $88.65\mathrm{g}$ of $\mathrm{Gold}$.