Calculate the number of ions in 0.585 grams of sodium chloride.

• Gram molecular mass of a compound is the amount of that compound that has the same mass in grams as the formula mass in atomic mass unit.
• When the formula mass of an ionic compound is determined by the addition of its component atomic masses and expressed in grams. It is called Gram formula mass.

As we know:

• Gram molecular mass of $\mathrm{NaCl}$=( $\mathrm{mass}\mathrm{of}\mathrm{Na}$+$\mathrm{mass}\mathrm{of}\mathrm{Cl}$)

=$(23+35.5)$

=$58.5g$

• So,$58.5g$ NaCl have ions =$2\times N_A$

=$0.585gofNaClhaveions$=$2\times N_A\times \frac{0.585g}{58.5g}$

=$0.02\times N_A$

=$0.02\times 6.022\times {10}^{23}$

=$1.20\times {10}^{22}$ions

Conclusion:

Hence, the number of ions in 0.585 grams of sodium chloride is equal to $1.20\times {10}^{22}$ions.