Question

BYB1. Calculate the amount (g) of 0.750 mmol of 4’-bromoacetophenone.

BYB2. Write a balanced equation for the reaction of 4’-bromoacetophenone and sodium hypochlorite.

BYB3. Calculate the amount of sodium hypochlorite (mmol) and the amount of concentrated Chlorox® bleach (g) required for the reaction of BYB2.

BYB4. Write a balanced equation for the reaction of sodium hypochlorite with sodium sulfite.

BYB5. Calculate the amount of sodium sulfite (mmol and g) required to quench the excess sodium hypochlorite by the reaction of BYB4.

BYB6. Calculate the amount of chloroform (mmol and g and mL) produced in the reaction of 4’- bromoacetophenone and sodium hypochlorite.

BYB7. Predict the amount (mL) of 1.5 M HCl required to neutralize (to pH 7) the strongly basic reaction mixture after the excess sodium hypochlorite quench. BYB8. Calculate the theoretical yield (g) of 4-bromobenzoic acid.

Answer 1

BYB1 mass of 4-bromoacetophenone = 0.750 mol x 199.045 g/mol = 0.150 g

BYB2 4-bromoacetophenone + 3NaOCl (in H2O) ---> 4-bromobenzoic acid + 3NaCl + CHCl3

BYB3 mmol of NaOCl required = 0.750 x 3 = 2.25 mmol

mass of chlorox required = 2.25 x 74.44 x 100/5.25 = 3.20 g

BYB4 Reaction,

NaOCl + Na2SO3 --> NaCl + Na2SO4

BYB6 mass of CHcl3 formed = 0.750 mmol x 119.38 g/mol/1000 = 0.09 g

BYB7 volume of HCl required = 0.750/1.5 = 1.5 ml

BYB8 Theoretical yield of 4-bromobenzoic acid = 0.750 x 201.02 g/mol = 0.151 g