Question

How many moles of Al₂S₃ will you make if you have 4.3 x 10¹⁶ moles of Li₂S in the following equation?

Li2S + AlCl3 → LiCl + Al2S3

Answer 1

Consider the balanced equation,

`3Li_2S + 2AlCl_3 to 6LiCl + Al_2S_3`

This is a simple stoichiometric calculation. We're relating stoichiometric coefficients to the molar quantity "reacted".

Hence,

`4.3*10^16"mol" * (Al_2S_3)/(3Li_2S) approx 1.4*10^16"mol"`

of `Al_2S_3` will be made from that amount of lithium sulfide assuming aluminum chloride is in excess.