3. (4 pts) The key step involves a base pulling off one of the benzylic hydrogens in the starting material. Given that the pK, of an alkane hydrogen is 2 50 and the pk, of a benzylic hydrogen is s 40, explain why potassium hydroxide can be used instead of sodium amide to synthesize 1,2-diphenylethyne from a vicinal dibromide. 4. (4 pts) Fill in the following table showing amounts to use and theoretical yield. Show your work. Amounts to Use Reactant Product from reaction of bibenzyl with NBS 1 mmol 340.05 g/mol Calculate and write in pre-lab notes. Product 1,2-diphenylethyne Moles Fill in 178.22 g/mol Calculate and write in pre-lab notes. This amount will be your theoretical yield. MW Amount