A mixture of9 mol Fz and 4 mol S are allowed to react. 3Fz+ S---+ SF6 How many moles ofFz remain after 3 mol ofS have reacted?

0 moles of F2

Explanation:

The equation of the reaction is given as;

3F2 + S ---> SF6

From the reaction above;

3 moles of F2 requires 1 mol of S to form 1 mole of SF6

How many moles of F2 would then require 3 mol of S ?

3 = 1

x = 3

x = 3 * 3 / 1 = 9 / 1 = 9 moles of F2

There would be no moles of F2 left as everything would be used up in the reaction.