A chemist warms 0.0500 mol of aniline with an excess of chloroform and alcoholic potassium…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A chemist warms of aniline with an excess of chloroform and alcoholic potassium hydroxide: . Use K = 39, O = 16, H = 1, C = 12, N = 14 and Cl = 35.5 in g/mol. Find the amount of potassium hydroxide that is used up. Find its mass. Find the mass of phenyl isocyanide, , at a yield of 100 %. Find the mass of potassium chloride formed.
Need a reminder? The key ideaShow
The amine lone pair attacks carbon atoms that are short of electrons. Primary and secondary amines are acylated. Only primary amines give the carbylamine reaction. Nitrous acid gives nitrogen gas with a primary aliphatic amine. At 273 K and 1 atm, one mole of gas has a volume of . Hinsberg's reagent gives an alkali-soluble sulphonamide with a primary amine, an insoluble one with a secondary amine and no product with a tertiary amine.
The worked solution
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. Potassium hydroxide. .
Step 2. Its mass. .
Step 3. Phenyl isocyanide. . The amount is , so the mass is .
Step 4. Potassium chloride. , and .
Answer: , , and .
Check. Atoms balance: all three chlorine atoms of the chloroform end as chloride, so is mol.
Safety. The isocyanide has a foul smell and is toxic, so this test is done in a fume cupboard on a very small scale.
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