1. What is the sum of the coefficients when the following is balanced?

Al(s) + HCl(aq) --> AlCl3(aq) + H2(g)

a) 13 b) 21 c) 18 d) 19 e) 11

2. Cryolite is a compound needed for the Hall-Heroult process for aluminum. Cryolite is produced by the following reaction:

6 HF + Al(OH)3 + 3 NaOH --> Na3AlF6 + 6 H2O

How many grams of Cryolite are produced if the reaction has a 67.3% yield and a limiting reagent of 35.4 grams of NaOH?

a) 61.9 b) 20.2 c) 41.7 d) 125 e)186

3. Iron Metal reacts with chlorine gas as follows:

2 Fe(s) + 3 Cl2(g) --> 2 FeCl3(s)

How many moles of FeCl3 are obtained when 4.6 mol of Cl2 reacts with excess Fe?

a) 1.5 mol b) 6.9 mol c)2.3 mol d) 4.6 mol e) 3.1 mol