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LogicX
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Homework Statement
Which of these compounds is significantly more basic than water?
I have 5 compounds here. I have (1) propane with a carbanion on the end, (2)the same molecule as that but with an adjacent double bond to oxygen (its on the middle carbon), (3) C-C-Ominus, (4) C-C-Sminus, and (5) Br-.
The Attempt at a Solution
I ranked their bascisity as (inc bascisity) 5<3<4<2<1. I am pretty sure this is correct, except that the thiolate has a lower pka than the alkoxide. Which means it should be a weaker base. But sulfur is less electronegative than oxygen so it can't stabilize the negative charge as well, so it should be more basic. So I guess the increasing size of sulfur which makes it more acidic is more important than electronegativity?
So, the pka of water, ethanethiol and ethanol are all generally around the same (14, 10.6, 16, respectively). Wheras propane is around 50. So I guess the answer would be the propane and acetone carbanions only?
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