Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
Butanamide, , is warmed with bromine and aqueous sodium hydroxide. The product is propan-1-amine. A chemist uses of the amide and collects the amine in a yield of . Use C = 12, H = 1, N = 14 and O = 16 in g/mol. Find the amount of amide, the mass of amine at a yield of 100 %, and the mass the chemist collects. Then find how many moles of sodium hydroxide are needed for the amount of amide, from the equation in the key idea.
The nitro group, the nitrile group and the amide group are reduced to a primary amine. A nitrile adds one carbon to the halide it came from. The Hofmann bromamide degradation removes one carbon: . The Gabriel synthesis makes pure primary aliphatic amines.
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Molar masses. Butanamide: . Propan-1-amine: .
Step 2. Amount of amide. .
Step 3. Amine at 100 %. One mole of amide gives one mole of amine: .
Step 4. Amine collected. .
Step 5. Sodium hydroxide. The equation uses 4 mol of NaOH for each mol of amide: .
Answer: , , and of NaOH.
Check. The amine has one carbon fewer than the amide, which is why its molar mass is lower by 28 g/mol.
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