1. Determine the following:

            a. The number of moles in 5.4 g of water

            b. The mass in grams of5.1x10^-2 moles of ZnSO₄.7H₂O

2. Aspirin (acetylsalicylic acid) is synthesized from salicylic acid and acetic anhydride according to the following equation:

             C₇H₆O₃   +    C₄H₆O₃     =     CgHaO₄    +    C₂H₄O₂

       salicylic acid   acetic anhydride   aspirin    acetic acid

Reactions involving organic chemicals often do not give stoichiometric amounts of products because of competing reactions and incomplete reaction. Thus the experimental yield is seldom above 90% of the theoretical amount and is usually lower than 90%.

          a. When 69 grams of salicylic acid were reacted with an excess of acetic anhydride, 72 grams of aspirin were obtained. Calculate the theoretical and percent yields for aspirin in this reaction.

           b. If 25 g of acetic anhydride had been used in the reaction above, which reagent would have been limiting and what would the theoretical yield of aspirin have been?

3. a. Reaction of 1.5 g calcium chloride with 3.4 g of silver nitrate gives 2.7 g of silver chloride. Write the balanced formula and net ionic equations for the reaction.

Determine the limiting reagent and the theoretical and percent yields of silver chloride.