4.75g(0.0125mol) of borax Na2b4O7*10H2) and 1 g(0.025mol) of sodium hydroxide in

Question

4.75g(0.0125mol) of borax Na2b4O7*10H2) and 1 g(0.025mol) of sodium hydroxide in 20 mL warm water.cool this mixture and slowly add 5.75 mL 30% hydrogen peroxide diluted with 15ml water. What is the theoretical yield in grams?

Qualitatively test approximately 0.1g samples of the sodium peroxoborate you have prepared:

a) To the 0.1g sample of the sodium peroxoborate, add 6mL of 0.1N HCl. To this acidified solution, add 0.1M KMnO4 solution dropwise. Observe the results; was Mn2+ or Mn4+ formed?

b) To another 0.1g sample of the sodium peroxoborate, add 6mL 0.1N HCl. To this acidified solution, add dropwise a fresh solution of 1.65g KI in 100mL water (0.165g KI in 10mL water if the KI is made up individually by each student). Observe the results.

Questions

2) Write a balanced equation for the synthesis of sodium peroxoborate according to the procedure you followed in this laboratory preparation.

3) Write balanced equations for the two qualitative tests you performed. Indicate whether Mn2+ or Mn4+ was formed in test (a)

4) If the solution of sodium metaborate prepared in this experiment is evaporated, borax will crystallize. Explain why this would happen.

5) Compare the structures of sodium peroxoborate and perchloric acid: draw the two structures and discuss their major differences both structural and reactivity-based, emphasizing the role of oxygen in both structures.

Explanation / Answer

4.75g(0.0125mol) of borax Na2b4O7*10H2) and 1 g(0.025mol) of sodium hydroxide in

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