Consider the following balanced chemical equation: 3(NH4)2CrO4 + 4Al + 24HCl --> 3CrCl2 + 6NH4Cl + 4AlCl3 + 12H2O.

Question

a) How many moles of HCl would be required for the reaction of 0.0123 moles Al?

b) How many grams Al would be required for the reaction of 2.00g (NH4)2CrO4?

All work must be shown.

Answer 1

a).
mols HCl = mols Al x (24 mols HCl/4 mols Al) = mols Al x (24/4) = ?

B).
Convert grams (NH4)2CrO4 to mols. mols = grams/molar mass
Using the coefficients in the balanced equation (as I did above in part a)convert mols mols (NH4)2CrO4 to mols Al.
Now convert mols Al to grams. g = mols x atomic mass.