Chemistry: Post your doubts here!

[The Sarcastic Retard]

anyone have a guess for practical 34??
plzz share

Paper is gonna be easy, but way lengthy.

 

[shahzaib9291]

Paper is gonna be easy, but way lengthy.

any idea about ions ?

 

[The Sarcastic Retard]

any idea about ions ?

Nope.
Why worrying?
Be cool..... You are prepared na??

 

[shahzaib9291]

Nope.
Why worrying?
Be cool..... You are prepared na??

yea just wondering

 

[saturn21]

Help needed

 

[hotdogandbuns]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w13_qp_43.pdf

I have a few problems with question 6.
First one is 6 ei) How many different dipeptides is it possible to synthesise, each containing two of the three amino acids alanine, serine and lysine?
I first thought 6 (which is correct) but then i looked at the structure of lysine. it has two NH2 groups so if peptide bonds can form at either NH2 wouldn't that make it 12?? Wouldn't joining the NH2 joined to (CH2)4 would form a diff molecule if joined to the NH2 that is from the CH???

Second one is f ii) Which of the structures G, H or J is identical to structure F?
I thought it was G. But its J. I have no idea why. No matter how you flip J it doesn't look like F.

EDIT: i dont get f iii) either, why cant i just switch the positions of NH2 and COOH. that looks different

Please help and thanks in advance

anyone? please?

 

[Cornflakes112]

View attachment 57270

Help needed

What's the answer?Is it C?

 

[lemonrsiow]

Hi guys, can anyone tell me what volumetric apparatus is? In MJ15/53 the answer for measuring 5cm^3 of liquid is to use volumetric apparatus, there's no mention of burette..

 

[nehaoscar]

Hi guys, can anyone tell me what volumetric apparatus is? In MJ15/53 the answer for measuring 5cm^3 of liquid is to use volumetric apparatus, there's no mention of burette..

Volumetric apparatus : anything you can measure volume in
eg: burette, measuring cylinder, syringe etc...

 

[Ãtìtúdê RöMéÔ]

nice job!

 

[The Sarcastic Retard]

https://www.xtremepapers.com/commun...1-and-9702-discussion-here.42450/#post-940854

 

[lemonrsiow]

Volumetric apparatus : anything you can measure volume in
eg: burette, measuring cylinder, syringe etc...

nehaoscar, so in the exam should I write volumetric apparatus or burette? Thanks.

 

[nehaoscar]

nehaoscar, so in the exam should I write volumetric apparatus or burette? Thanks.

Burette... for the paper they want as exact answers as possible with clear detail
Volumetric apparatus just means that the examiner should accept any apparatus stated by the student whether it be burette or measuring cylinder

 

[saturn21]

What's the answer?Is it C?

Yup

 

[Wolfgangs]

How to find the answer in this question?

 

[The Sarcastic Retard]

How to find the answer in this question?

Which board?

 

[The Sarcastic Retard]

13, 16, 17, 24 and 39
w05 paper 1
Metanoia

 

[Wolfgangs]

Which board?

CIE

 

[♣♠ Magnanimous ♣♠]

13, 16, 17, 24 and 39
w05 paper 1
Metanoia

for 13 ans is D?
16 and 17 not sure :')
24 C

and 39 all three are correct

Am I right?

 

[The Sarcastic Retard]

for 13 ans is D?
16 and 17 not sure :')
24 C

and 39 all three are correct

Am I right?

13 is correct, rest are wrong.