Synthesis of Co(NH3)6Cl3

Name:_____________________________ Date_________________

Write answers in full sentences . Show all calculations required to get the answer.

1) (1pt.) Write down the overall chemical equation for the synthesis of Co(NH3)6Cl3, Why can’t you simply mix all ingredients together ?

2) (1pt.) How many chemical reactions do occur during the synthesis of Co(NH3)6Cl3 ?

3) (1pt.) What experimental technique is used to purify the product?

4) (1pt.) Suggest couple methods that could be used to confirm the identity of the isolated product. (Recall information learned in Chem 113 lab and Chem 113 lecture.)

5) (6 pts.) In the synthesis of Co(NH3)6Cl3 student used 8.9 g of CoCl2.6H20, 5.7 g of NH4Cl, 21 ml of concentrated ammonia and 12 ml of 35% solution of hydrogen peroxide. After the recrystallization student isolated 2.5 g of the desired product. Answer the following questions. Show all calculations.

a) (1) How many moles of CoCl2.6H2O were used in the synthesis? (2) How many moles of the product would be formed if this compound was the limiting reagent?

b) (1) How many moles of NH4Cl were used in the synthesis? (2) How many moles of the product would be formed if this compound was the limiting reagent?

c) (1) How many moles of NH3 were used in the synthesis? “Concentrated ammonia” is 15 M NH3 in water. (2) How many moles of the product would be formed if this compound was the limiting reagent?

d) (1) How many moles of H2O2 were used in the synthesis? 35% H2O2 contains 35 g H2O2 / 100mL solution. (2) How many moles of the product would be formed if this compound was the limiting reagent?

e) Which compound is the limiting reagent? Explain why.

f) What is the theoretical yield of the reaction?

g) What is the actual yield of this reaction?

h) What is the %yield of the reaction?