Edexcel - Chemistry Unit 2 - 4 June 2013

why are tertiary alcohols more reactive?

why are tertiary alcohols more reactive?

It's down to the positive inductive effect of surrounding alkyl groups.

has 3 R groups and R groups break the c-x bond quickly cos 3 is more than 2 r groups (secondary) or 1 r group (primary)

A bit of reaction mechanism practice; would anyone like to explain the procedure of producing a carboxylic acid from ethane? (Hint: there are multiple steps.. )

I am really sorry if this is a dumb question but why does the c-x bond break more quickly?

but why does this make it more reactive?

ethane + (uv) + cl₂ -> CH₂CHCl + NaOH_(aq) -> CH₂CHOH + KCr₂O₇ + H₂SO₄ (reflux). Distil final mixture and dry with anhydrous sodium sulfate.

The grade boundaries are scary for this exam..

whyy what are they like roughly??

The 3 alkyl groups feed their electrons to the carbocation, hence, it forms a much more stable intermediate that primary and secondary alcohols, it's therefore more 'available' to react - the fact theres 3 alkyl groups also means the halogen group can leave easier. That's my understanding at least.



Very good.

But! You're missing a hydrogen in your haloalkane.

Its been slowly creeping up, it was 63/80 in June 2012 and now 65/80 for Jan 2013's paper (which was real hard in my opinion). That is really insane considering its a paper where mistakes can be made so easily

Baiscally, Alkyl groups are e- donating groups so

primary - 1 R group present
secondary - 2 R groups present
tertiary - 3 R groups present

so because tertiary has more R' groups (electron donating groups) than secondary or primary, it breaks the c-x bond quicker

A quick question, in unit2 chem jan 12 question 21 b (ii) , the reaction between KOH(aq) and a primary and tertiary halogenoalkane(they are isomers of eac hother) is different in terms of the mechanism and the intermediate formed...i think it has something to do with the 1 step and 2 step mechanism but im not too sure, also why does the structure of the halogenoalkane effect the mechanism? If someone could look at the question it would really help thank you.

A bit of reaction mechanism practice; would anyone like to explain the procedure of producing a carboxylic acid from ethane? (Hint: there are multiple steps.. )