Explanation:
It is known that number of moles is the amount of mass present in a given molar mass of the substance.
Mathematically, No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
We are given that mass of [tex]AlCl_{3}[/tex] is 0.255 g and molar mass of [tex]AlCl_{3}[/tex] is 133.34 g/mol.
Therefore, number of moles of [tex]AlCl_{3}[/tex] is calculated as follows.
No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
= [tex]\frac{0.255 g}{133.34 g/mol}[/tex]
= [tex]1.912 \times 10^{-3}[/tex] mol
Since, there are three chlorine atoms present in one mole of [tex]AlCl_{3}[/tex]. Therefore, moles of chlorine ions present in given 0.255 g will be calculated as follows.
[tex]3 \times 1.912 \times 10^{-3}[/tex] mol
= [tex]5.736 \times 10^{-3} mol[/tex]
Thus, we can conclude that [tex]5.736 \times 10^{-3} mol[/tex] chloride ions are in 0.2550 g of aluminum chloride using [tex]AlCl_{3}[/tex]'s molar mass of 133.34 g/mol.
