• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Chemistry Paper 4-theory- doubts =D

C

cheondoongiee

Messages
5
Reaction score
5
Points
13
Enzymes are proteins, right? So in their tertiary structure they have ionic bonds. When the pH is increased or decreased, it affects the ionic bonds in the tertiary structure. This can result in the active site changing and reducing enzyme activity or even denature it.
 
L

leosco1995

Messages
971
Reaction score
532
Points
103
Please help. I know the value of J is 21 but I couldn't figure out K.
 

Attachments

  • qorganic.png
    qorganic.png
    45.5 KB · Views: 14
C

cheondoongiee

Messages
5
Reaction score
5
Points
13
haroon740

haroon740

Messages
164
Reaction score
230
Points
53
cheondoongiee said:
I think it's like this- so in K the reaction is basically the first one right? RCH3 -> RCH2Cl. But you'll notice in the product, there's actually 9 places that Cl could have been put in. It can replace all the hydrogens in the methyl groups. So it becomes 1x9, and the ratio is 21:9.
Click to expand...
seems legit :p
 
C

cheondoongiee

Messages
5
Reaction score
5
Points
13
cheondoongiee said:
I think it's like this- so in K the reaction is basically the first one right? RCH3 -> RCH2Cl. But you'll notice in the product, there's actually 9 places that Cl could have been put in. It can replace all the hydrogens in the methyl groups. So it becomes 1x9, and the ratio is 21:9.
Click to expand...
If that didn't make sense count the number of hydrogens- it's 9. There's 9 places that the Cl could have been put in so it's 1x9. Hope this helps!
 
iKhaled

iKhaled

Messages
870
Reaction score
374
Points
73
Anika Raisa said:
ON12 no.7bii wudnt it be suspect 1 because u c his fingerprints were found in both crime scenes!!! I just donot get y ms says suspect 2!! N they didn’t give valid reason 2!!! Btwn if its suspecvt 2 then his finger print ws only found in scene 1 not scene 2!!!
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

Any 1 any idea!! Thank u!!!
Click to expand...
lol yeah i spent like 30 mins on this question figuring out why the mark scheme is saying the complete opposite and at the end i dont know why..i bet the examiner is a foolish inspector so he doesn't know these kind of stuff :p
 
P

PhyZac

Messages
681
Reaction score
1,731
Points
153
Anika Raisa said:
ON12 no.7bii wudnt it be suspect 1 because u c his fingerprints were found in both crime scenes!!! I just donot get y ms says suspect 2!! N they didn’t give valid reason 2!!! Btwn if its suspecvt 2 then his finger print ws only found in scene 1 not scene 2!!!
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

Any 1 any idea!! Thank u!!!
Click to expand...
I got it as suspect when i solved...i dont know why..but it as similar the crime scene 1..
i know this isnt useful...
 
M

mariyam95

Messages
114
Reaction score
36
Points
38
haroon740 said:
PLEASE ANYONE SOLVE THIS QUESTION NO 2 part B of this paper ---ughh frickin annoyin
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w08_qp_4.pdf
Click to expand...
Hey dude how are you ... Long time no see in tutions :p
So about ur question im gonna explain it to u even though it makes no sesnse at all

Look at step 1 ... a is for h2o2 b is for I- and c is for H+

In the first step h2o2 has appered once so right 1 in the first row of a
I- has appered one in the equation so put 1
And H+ is not there so put zero

For step 2 H2O2 is not there but still u have (1) in the first box so put another one because it was shown in the first step
For I- the same thing ..not shown in step 2 but u already has one from the spfirst step so put another 1
For hydrogen ion this time its shown in step 2 so put 1

For step 3
H2o2 u already has 1 from step 1 so put 1
I- is shown in step 3 and step 1 so put 2 because now u have 2 I- shown
H+ is shown in step 3 and step 2 so in total its shown twice so put 2

Thats it ..hope it hepls :)
 
P

PhyZac

Messages
681
Reaction score
1,731
Points
153
iKhaled said:
lol yeah i spent like 30 mins on this question figuring out why the mark scheme is saying the complete opposite and at the end i dont know why..i bet the examiner is a foolish inspector so he doesn't know these kind of stuff :p
Click to expand...
come on...it is so clear.

Suspect 2 clearly, has similar fragments as crime scene 1
 
iKhaled

iKhaled

Messages
870
Reaction score
374
Points
73
ok guys a question..whoever gets it correct without cheating :p gets a free candy or a cookie ur choice

what is the test that will distinguish methanol from ethanol ?
 
M

mariyam95

Messages
114
Reaction score
36
Points
38
iKhaled said:
ok guys a question..whoever gets it correct without cheating :p gets a free candy or a cookie ur choice

what is the test that will distinguish methanol from ethanol ?
Click to expand...
Using NaoH + I2 (iodine)
Ethanol gives yellow ppt and no rxn with methanol
 
You must log in or register to reply here.
Top