Question

Here is a link just click on it and scroll down to question number 25

http://papers.xtremepapers.com/CIE/Cambridge%2520International%2520A%2520and%2520AS%2520Level/Chemistry%2520(9701)/9701_s09_qp_1.pdf

Answer 1

The answer is B and it does not make sense to me

Answer 2

Doesnt adding NaOH to a halogenalkene Gives you a alcohol and Sodium halogen???

Answer 3

If so then why are they saying a you get a alkene????

Answer 4

@kainui @emcrazy14 @chmvijay

Answer 5

The directory ./CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s09_qp_1.pdf/ does not exist.
Continue.


can't access it.

Answer 6

Ok i took a snapshot

Answer 7

well.. which one makes no sense at all, you honestly don't need to know much to figure this out.

Answer 8

Its option B

Answer 9

Nice job! that's correct. Do you know why?

Answer 10

I know the Answer already!
What asking is why????

Answer 11

What I'm asking*

Answer 12

A - Alkenes react with concentrated sulphuric acid in the cold to produce alkyl hydrogensulphates. Ethene reacts to give ethyl hydrogensulphate. All you need to do is to learn the structure of sulphuric acid. A hydrogen from the sulphuric acid joins on to one of the carbon atoms, and the rest joins on to the other one. Make sure that you can see how the structure of the sulphuric acid relates to the various ways of writing the formula for the product.
C - In elimination reactions, the hydroxide ion acts as a base - removing a hydrogen as a hydrogen ion from the carbon atom next door to the one holding the bromine.
D - If ethanol vapour is passed over heated aluminium oxide powder, the ethanol is essentially cracked to give ethene and water vapour

Answer 13

okaaaay in
A= propan-1-ol + conc H2SO4 -> propene
because conc H2SO4 eliminates H2O from alcohol

C= 1-bromopropane + ethanolic NaOH -> propene
ethanolic NaOH, Na takes Br = NaBr and H is taken by OH to form H2O

D= propan-2-ol vapour + heated aluminium oxide -> propene
heated aluminium oxide is a catalyst that eliminates H2O from propan-2-ol

lastly B is the answer because
aqueous sodium hydroxide+ 2-bromopropane -> this is Nucleophilic substitution thus OH from NaOH substitutes Br in 2-bromopropane and so the product will be alcohol and Br- ion
:D

Answer 14

Thank god! you finally came!! Come to skype! @Somy
Problem is that I didn't quite get what is exactly the question was asking, the fact that is it asking for which does NOT give propene or just more than 1 product but I think from the explanation I understood what the question is asking and therefore why the answer is B

Answer 15

@kl-rc np i'll be there soon :)