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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Bozo on May 14, 2011, 09:21:28 pm

Title: Bozo's question thread
Post by: Bozo on May 14, 2011, 09:21:28 pm

Hey all.

Its that time of the year where revision has begun and I'm going through checkpoints and past exam questions.

First up, I came across this question i don't understand in checkpoints 2011.

See attached.


Thanks in advance guys.

Title: Re: Bozo's question thread
Post by: tony3272 on May 14, 2011, 10:25:24 pm

First thing you can notice with this is that it's a carboxylic acid, hence it will react with methanol to form an ester. Tick for that.
Next you can see that there is a carbon-carbon double bond. It will have similar properties to that of an alkene. This means it can undergo an addition polymerisation with ethene. Tick there.
This also means it can undergo an addition reaction with the Br2. Last tick there.
Hence the answer is choice A  :)
Just check you reaction pathways if you're not sure about this stuff.

*edit* i rewrote something twice :P

Title: Re: Bozo's question thread
Post by: Bozo on May 31, 2011, 08:04:44 pm

Question 13
The following tests were performed on organic compound X:
• Mixing with Br2(aq) produces a colourless solution
• Reaction with CH3COOH in the presence of H2SO4 yields a sweet-smelling product
• Oxidation using MnO4
–/H+ produces a solution which reacts with NaOH(aq)
Which of the following is least likely to be Compound X?
A. CH3CH=CHCOOH
B. HOCH2CH2CH=CHCH3
C. HOCH2CH=CHCH2COOH
D. CH3CH=CHCH2OH

Title: Re: Bozo's question thread
Post by: luken93 on May 31, 2011, 08:24:06 pm

Mixing with Br2 = Double Bond Present
Sweet Smelling = Ester Formed = Carboxylic Acid + Alcohol = Alcohol
Oxidation = Primary Alkanol

Therefore, A is the least likely, as it only satisfies one of the criteria (double bond)