Cambridge International 2016 Chemistry (9701) Paper 2

OP

Original post by Dohaeris

Yep, I've got the new book. To be honest, I'm just worried that they'll bring a couple of the ridiculous questions I can never seem to figure out, like some of the ones where we have to deduce a structure using the NMR spectrum.

But still, the grade threshold for an A is usually in the 60 to 70 range, so we should still be able to get As

True that! but I'm sure the questions on NMR will be easy. Its part of the new syllabus! But our teacher showed us grades of some girls in our school who got in 90's!

For bio, did you finish past papers? Our teacher told us not to bother too much about them and focus on just revising the content as it's too much.

Reply 23

OP

Original post by Shamita

I did chemistry paper 22 as well
For question 1, we have to use the information in the table to find the nucleon number like for nitrogen, the nucleon number was 15 because the number of neutrons was 8 and number of protons was 7. Evem i was shocked when i saw the atomic number of boron was 4.
For the value of x, i got 2
What did u all get

But I found the first part tricky because of this.
I got 3. but I guess I will get ecf?

Reply 24

Original post by Emad Nasir

(for p22) Yes You seem to be right, The table looked kinda tricky at first but then you should know that the particles given were mostly either isotopes or ions. for isotopes we know that the protons are same so the nucleon number seemed to be different so atomic mass was mostly the same and we had to calculate everyhthing compared to the table data.
Thank God, I got x = 2 as well, is it the same x for xH2O ?
and what about ionic equations i think i did something wrong? and bond energy of ICL Bond? and the pattern for Mg Al and Si eith their chloride .... what were we supposed to write in that?

Yes, the x is for xH2O. The ionic equations for the reaction of halides??
For the first one, I wrote Ag+(aq) + Cl- (aq) gives AgCl(s)
For the second one , I wrote Ag+(aq) + 2NH3(aq) gives [ Ag(NH3)2]+
For the bond energy, I got 220.5
For the pattern, I wrote the number of chlorine atoms in the ionic compound increases because the oxidation number increases from Mg to Si, so more chlorine atoms are needed to gain the electrons.
What did u write for them?

Reply 25

Original post by A.S.J

But I found the first part tricky because of this.
I got 3. but I guess I will get ecf?

Can I know how did u balance the equation? Like did u balance the electrons or the number of atoms of each element ? Because the calculation to find x is related to the equation rite?

Reply 26

Emad Nasir

I think i did not write the second ionic equation correct, and yes 220.5 is correct although i got it wrong. I am still unsure what were we supposed to write in the pattern, i wrote abouth the ionic bonding , covalent bonding , hight temperature and melting point etc. And the equation balancing? how did you do that? i think i got it right but need to confirm

Original post by Shamita

Yes, the x is for xH2O. The ionic equations for the reaction of halides??
For the first one, I wrote Ag+(aq) + Cl- (aq) gives AgCl(s)
For the second one , I wrote Ag+(aq) + 2NH3(aq) gives [ Ag(NH3)2]+
For the bond energy, I got 220.5
For the pattern, I wrote the number of chlorine atoms in the ionic compound increases because the oxidation number increases from Mg to Si, so more chlorine atoms are needed to gain the electrons.
What did u write for them?

Reply 27

Original post by A.S.J

True that! but I'm sure the questions on NMR will be easy. Its part of the new syllabus! But our teacher showed us grades of some girls in our school who got in 90's!

For bio, did you finish past papers? Our teacher told us not to bother too much about them and focus on just revising the content as it's too much.

I've done a bunch of bio past papers, but just to get an idea of the structure and making sure my timing is on point. And then a bunch of my time was spent memorising that endless content. I have most of it under my belt, though I do forget a few details here and there. I suppose it can't be avoided.

Has your teacher told you anything about the new paper 4 structure for chemistry? It'll be different this year.

Also, I'm quite sure NMR spectrum was on the previous syllabus. It's included on a bunch of past papers, isn't it?

Reply 28

Original post by Emad Nasir

I think i did not write the second ionic equation correct, and yes 220.5 is correct although i got it wrong. I am still unsure what were we supposed to write in the pattern, i wrote abouth the ionic bonding , covalent bonding , hight temperature and melting point etc. And the equation balancing? how did you do that? i think i got it right but need to confirm

We have to write the overall equation to find x. The first equation had 6 electrons on the reactants side. The second equation had 2 electrons on the product side. So i multiply the whole second equation by 3. Now the 6 electrons can be cancelled. I wrote the reactans if both equations together and the products together.

Reply 29

Original post by Shamita

We have to write the overall equation to find x. The first equation had 6 electrons on the reactants side. The second equation had 2 electrons on the product side. So i multiply the whole second equation by 3. Now the 6 electrons can be cancelled. I wrote the reactans if both equations together and the products together.

Of both **

Reply 30

Emad Nasir

Original post by Shamita

We have to write the overall equation to find x. The first equation had 6 electrons on the reactants side. The second equation had 2 electrons on the product side. So i multiply the whole second equation by 3. Now the 6 electrons can be cancelled. I wrote the reactans if both equations together and the products together.

I did the exact thing :smile:

well the rest of the paper was very easy

Reply 31

OP

Original post by Shamita

Can I know how did u balance the equation? Like did u balance the electrons or the number of atoms of each element ? Because the calculation to find x is related to the equation rite?

Original post by Shamita

We have to write the overall equation to find x. The first equation had 6 electrons on the reactants side. The second equation had 2 electrons on the product side. So i multiply the whole second equation by 3. Now the 6 electrons can be cancelled. I wrote the reactans if both equations together and the products together.

That is exactly what I did and I got 3.

I think I have made many weird silly mistakes:/ And I am scared now.

Reply 32

OP

Original post by Dohaeris

I've done a bunch of bio past papers, but just to get an idea of the structure and making sure my timing is on point. And then a bunch of my time was spent memorising that endless content. I have most of it under my belt, though I do forget a few details here and there. I suppose it can't be avoided.

Has your teacher told you anything about the new paper 4 structure for chemistry? It'll be different this year.

Also, I'm quite sure NMR spectrum was on the previous syllabus. It's included on a bunch of past papers, isn't it?

Well, he just said to look at the specimen paper, he gave it to us.

That's true for biology though. My biology teacher said not to bother too much with papers and just revise cuz many people end up not revising enough but just doing papers that don't really help.

I think better than biology I have chemistry under control!
We have Carbon 13 new. Oh and why is D20 used?

I'm so scared as I have an exam tomorrow and then the next day bio then chem:/

Reply 33

Original post by A.S.J

Well, he just said to look at the specimen paper, he gave it to us.

That's true for biology though. My biology teacher said not to bother too much with papers and just revise cuz many people end up not revising enough but just doing papers that don't really help.

I think better than biology I have chemistry under control!
We have Carbon 13 new. Oh and why is D20 used?

I'm so scared as I have an exam tomorrow and then the next day bio then chem:/

Really? I think biology is a lot easier than chemistry. Chemistry seems much more unpredictable

What do you have tomorrow?

D2O is the same as H2O, except the deuterium ion (D) is used instead of hydrogen. This is done because NMR spectrums are based on hydrogen, so if H2O was used, the hydrogens in it would affect and confuse the spectrum, producing weird peaks.

Also, adding D20 tells you which peaks are produced by -OH or -NH groups.

Reply 34

OP

Original post by Dohaeris

Really? I think biology is a lot easier than chemistry. Chemistry seems much more unpredictable

What do you have tomorrow?

D2O is the same as H2O, except the deuterium ion (D) is used instead of hydrogen. This is done because NMR spectrums are based on hydrogen, so if H2O was used, the hydrogens in it would affect and confuse the spectrum, producing weird peaks.

Also, adding D20 tells you which peaks are produced by -OH or -NH groups.

I seem to know A2 chemistry better than A2 biology. I don't know why. I guess it is because of the question structure in biology.
Oh and, for biology, did your teacher tell you any thing about learning all the enzyme names and all those names in genetic technology? In gene therapy , gene diversity, mutations and all. I asked mine so many times she didn't reply.
so we learn all the names which factor effects what right? I've already learnt it, but want to be on the safe side.

Where I live, we have to do a ministry exam for qualification for the country, so I have Islamiat exam tomorrow.

Got it. Thanks!

Reply 35

Original post by A.S.J

I seem to know A2 chemistry better than A2 biology. I don't know why. I guess it is because of the question structure in biology.
Oh and, for biology, did your teacher tell you any thing about learning all the enzyme names and all those names in genetic technology? In gene therapy , gene diversity, mutations and all. I asked mine so many times she didn't reply.
so we learn all the names which factor effects what right? I've already learnt it, but want to be on the safe side.

Where I live, we have to do a ministry exam for qualification for the country, so I have Islamiat exam tomorrow.

Got it. Thanks!

What enzyme names are you talking about? Like Taq polymerase, DNA Ligase and that stuff?

If so, yes I think so.

Reply 36

OP

Original post by Dohaeris

What enzyme names are you talking about? Like Taq polymerase, DNA Ligase and that stuff?

If so, yes I think so.

No no. I know we are supposed to know Taq polymerase.
My bad.
I meant stuff like Tyrosine and DOPA for Albinism.
And my teacher said that all the equations will be given. True?
I'm a bit scared on the evolution classification chapters. I need to go over them so many times:/

Reply 37

Original post by A.S.J

No no. I know we are supposed to know Taq polymerase.
My bad.
I meant stuff like Tyrosine and DOPA for Albinism.
And my teacher said that all the equations will be given. True?
I'm a bit scared on the evolution classification chapters. I need to go over them so many times:/

I'm not sure about those, so I memorised them just in case.

I feel like that part of striated muscle fibres is going to be questioned a lot. I think it's new on the syllabus, because I haven't seen a past paper question about it.

Reply 38

OP

Original post by Dohaeris

I'm not sure about those, so I memorised them just in case.

I feel like that part of striated muscle fibres is going to be questioned a lot. I think it's new on the syllabus, because I haven't seen a past paper question about it.

Okay, Thanks. I asked because they are more like examples, and its new so I don't know to what extent we need to learn.

Same! I even feel Genetics is going to be questioned. Especially the technology part, about DNA extractions and stuff.

So are you prepared for tomorrow and the day after?
I'm just so scared...

Reply 39