Question

9. Determine the amount of product. Do not forget units.

How much lithium chloride (in grams) can be produced using 20 grams of lithium hydroxide? Answer in three significant digits. (5 points)

LiOH         +         KCl        à         LiCl        +        KOH

Answer 1

LiOH + KCl ------------> LiCl + KOH

According to the stoichiometry of the reaction, 1 mole lithium hydroxide produces 1 mole lithium chloride. Thus, the number of moles of LiOH is equal to number of moles of LiCl at the completion of the reaction.

That is, number of moles of LiOH = number of moles of LiCl –statement 1

Now,

Number of moles of LiOH = mass of LiOH / Molecular mass of LiOH

                                    = 20 g / 23.947 g mol^-1

                                    = 0.835 moles

Thus, number of moles of LiCl produced = 0.835 moles                         [statement 1]

Mass of LiCl produced = moles of LiCl x molecular mass of LiCl

                                    = 0.835 moles x 42.390 g mol^-1 = 35.40

                                    = 35.4 g