Answer:
73.81 fg
Explanation:
1. Calculate the number of Al₂Cl₆ molecules
[tex]\text{No of molecules} =1.000 \times 10^{9}\text{ atoms Cl}\times \dfrac{\text{ 1 molecule Al$_{2}$Cl}_{6}}{\text{6 atoms Cl }}\\\\ =1.667 \times 10^{8} \text{ molecules Al$_{2}$Cl}_{6}[/tex]
2. Calculate the moles of Al₂Cl₆
[tex]\text{No. of moles} = 1.667 \times 10^{8}\text{ molecules} \times \dfrac{\text{1 mol}}{6.022 \times 10^{23}\text{ molecules}} =2.768 \times 10^{-16} \text{ mol}[/tex]
3. Calculate the mass of Al₂Cl₆
[tex]\text{Mass} = 2.768 \times 10^{-16} \text{ mol} \times \dfrac{\text{266.68 g}}{\text{1 mol}} = 7.381 \times 10^{-14}\text{ g}= \textbf{73.81 fg}[/tex]
