Chemistry Unit 6B 15.05.2013!! June 2013

[tasmiah2310]

what is d range for A?in d previus years

Umm.. from 34..to 38 I guess

 

[Adam94]

June 2011 was effin hard bro. :O

Not as hard as this one, when i did the past paper for the 2011 i got above A but for the one we did today i don't think thats going to happen :|

 

[Nofel Mehmood]

Not as hard as this one, when i did the past paper for the 2011 i got above A but for the one we did today i don't think thats going to happen :|

Well, I found 2011 may even harder. :S

 

[AsimZZZ]

Guys what did you answer about the side chain in the nmr question???

 

[Ni7san]

june 11 was much easier

 

[Adam94]

i am not sure about the side chain but i I wrote CH2CH2COCH3. Most probably incorrect

 

[Ni7san]

i think 32 should be an A.Fingers crossed.Then there will be a small chance for me to get an A

 

[yousef0074]

Yup

i am not sure about the side chain but i I wrote CH2CH2COCH3. Most probably incorrect

what was used to measure volume?? I wrote burette. And for structural formula of X, i included the benzene ring.Is it correct?

 

[Nofel Mehmood]

Screw this, any leaks for Physics unit 6?

 

[Adam94]

Yup
what was used to measure volume?? I wrote burette. And for structural formula of X, i included the benzene ring.Is it correct?

I said pipette because it can read to a precision of 0.1 and the value was given like this i think 24.0, i can't remember the value but the concept is the same. And it can read to a precision of 0.1. Usually for burette you would use it if it is given like this 24.00

 

[pineapplelynn7]

I said pipette because it can read to a precision of 0.1 and the value was given like this i think 24.0, i can't remember the value but the concept is the same. And it can read to a precision of 0.1. Usually for burette you would use it if it is given like this 24.00

oh noooo i wrote burette because the volumes had to be accurate. precision never came across my mind. now i remember - the values were given to 1 dp.

 

[Aaron Rodrgp]

for the nmr structure, i got 'OH-benzene ring-CH2CH2COCH3'

 

[Aaron Rodrgp]

oh noooo i wrote burette because the volumes had to be accurate. precision never came across my mind. now i remember - the values were given to 1 dp.

THATS EXACTLY THE SAME MISTAKE I MADE

 

[Aaron Rodrgp]

Unit 6B Physics Predictions anyone?

 

[Aaron Rodrgp]

I suggest you read through every experiment marked 'experiment' in the hodder a2 physics textbook. every past paper experiment has been taken from that book.

 

[qstar.inc]

Yup
what was used to measure volume?? I wrote burette. And for structural formula of X, i included the benzene ring.Is it correct?

i wrote burrette too

 

[Adam94]

for the nmr structure, i got 'OH-benzene ring-CH2CH2COCH3'

Do you think our answers are correct ? It makes sense as there will be no splitting on CH3 group
I didn't show the OH because they only wanted you to the side chain

 

[6yrsoldphysicist]

Hi Guys, I have a few questions about the paper,

1.) For the glucose one,
-I think the order of glucose is 0, and 1 for H2SO4 and KMnO4
Did you guys happen to know how to express the rate equation? I wrote rate = k[H+][MnO4 -], or do you have to put everything into it?
-What another technique did you put to measure the conc. of KMnO4 continously? I putted colorimetry....
-And the color change at the end point should be purple to pink?

2.) The middle part of the first question, it said when Ni(H2O)6 reacts with excess HCl, a brown yellow solution forms, I thought [NiCl4]2- was green :<

3.) For those % error thingy, did you guys get 0.x% or something? Did you need to round it up to a real number?

4.) The NMR. I thought there were only 5 peaks, containing 2 multiplet,
I putted HO-benzene ring- CO C(CH3)2 H

5.) Finally, how did all of you outline "how Solvent Extraction allow us to obtain X" ?
I panicked on this one, and stupidly answered the following
- Allow time for mixture to reach equilibrium and form 2 layers
- X will be the bottom layer as its density is 1.4x
- Open tap of separating funnel and obtain x and close tap at where 2 layers meet ......

 

[Adam94]

I said the colour change was from colourless to pale pink . I wrote colorimetry aswell
For error thing it was 0.x something. For the nmr they said there were 6 peaks

Solvent extraction
i said open the tap to allow the two layers to separate, didn't specify which one and then again put the separated into a separating funnel and add Sodium carbonate... Not sure about this one though

 

[Aaron Rodrgp]

I FAILED!!!

my gradient was -10000

i wrote it as 8.31 x 10^4 . will that show up a problem?

not at all...the answer is still the same