Chemistry unit 6 June 2016

Why is this the answer:
It contains a phenol group/has OH attachedto benzene ring.

I wrote x contains a Cl^-

We know that the compound contains a benzene ring. If we try and react benzene with bromine water, we will get no reaction as the electron density of the benzene ring is not high enough to form the required Br+ electrophile, so if you wanted to brominate benzene you would need to generate Br+ in another way. In comparison, in phenol the lone pairs of the oxygen are partially delocalised into the ring system giving it a much higher electron density, such that it can polarise the Br-Br bond sufficiently for an electrophilic substitution reaction to occur. After one bromine has added, it is possible for another 2 to substitute onto the ring, and for reasons you don't need to know they will always be in position 2,4,6 so you get 2,4,6-tribromophenol (or a variant of this) which is a white precipitate

The test for phenol is that it forms aN INSOLUBLE white ppt. with bromine solution!

What does everyone think about Q.3 January 2016, was it SO HORRIBLE or is it just me ?

For some reason I can't work out the initial rate

So for the order of potassium manganate I know you'll have to look at A and B. So the volume will be halved

For the order of Glucose, you look at A and C, so the volume will be doubled.

And for the order of Sulfuric acid, you look at C and D, so the vol will be halved.

Now how do I work out the initial rate cos they're quite small and hard to compare??

The whole paper seems like an anomaly tbh

Why do you need to find the initial rate when they just ask for rate equation?? which is Rate=k[H+][Mno4-] as reaction is zero order w.r.t to glucose

The whole paper seems like an anomaly tbh

i'd rather call it toxic and hazardous!

Is the examiner report wrong?
It says that the voltmeter is incorrect but they've included it in mark scheme

Which paper is this?

I guess just 'voltmeter' would be penalised.

Depends, what do you exactly mean by basic one ?

Is the examiner report wrong?
It says that the voltmeter is incorrect but they've included it in mark scheme

Thank you!!!!

No it is correct. Using a voltmeter is not wrong, using voltmeter W is wrong as it is low resistance, whereas we want a voltmeter with infinitely high resistance (since if you do physics from product/sum rule the resistance of the 2 things in parallel will tend to the resistance of the thing the voltmeter is across, meaning that it doesn't effect the voltage across the component (as potential divider)). If you don't do physics ignore all that and just learn that voltmeters should have high or ideally infinite resistance

Most welcome! All the best for tomorrow.

Thank you guys so much, I have been stuck on this for ages and it didn't cross in my mind that it would be related to full 3d sub-shell

What does everyone think about Q.3 January 2016, was it SO HORRIBLE or is it just me ?

In steam distillation, where would the crushed lavender flower be,

In the first flask with the boiling distilled water or the second one?