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Help on esters

file:///C:/Users/44770/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/Aromatic%20and%20Carbonyl%20Chemistry%20Assessment%20(1).pdf

question 4 e specifically

(edited 4 years ago)

assessment.png76.2KB

Reply 1

medscorer2020

The link is not working

Reply 2

Powerzolt

i'll send a photo then

Reply 3

Frank Peters

someone gives us an answer. I'm a second year undergrad Chemist and I dont flipping know this (crying face emoji)

Reply 4

1st superstar

@Pigster or @Deggs_14 might be able to help

Reply 5

Powerzolt

I have an answer of adding tollen's reagent to it which oxides the aldehyde to a carboylic acid then just heating the product with methanol and conc h2so4 to form the ester but idk if correct

Reply 6

Ðeggs

Oxidise the 2-methylpropanal into 2-methylpropanoic acid using K₂Cr₂O₇acidified by H₂SO₄.
Then react the carboxylic acid with methanol to produce the ester at RTP with a few drops of an acid catalyst.
I don't know about the maths element though.

(edited 4 years ago)

Reply 7

Powerzolt

I got 3.6g for the math part

Reply 8

Tech1017

I do edexcel so for the sythesis im not sure what this examboard is but you need to make the 2-methylpropnal into a carboxylic acid using sulfuric acid and potassium dichromate and heat under reflux.Then react the carboxylic acid methylpropanoic acid with methanol using an acid catalyst like sulfuric acid and heat under reflux to make ester C.Im not too sure on the maths but I think you need 22.5g of 2-methylpropanal as you work out the moles of ester c used which is 12.75 / 102 = 0.125The yield of 2-methylpropanal is 40%So the moles of it is timed by 0.4 to make the moles of ester C 1:1 ratioSo 2-methyl.. is XX * 0.4= 0.125So X= 0.125/0.4X=0.3125Tmes this by mr of 2-methyl.. 0.3125*72=22.50g