HL Chemistry paper 1 and 2

[Klauu]

 

 

(TZ2) I'm super frustrated with the amount of silly errors I made in paper 2 (not reading the question properly, unit conversions etc.) I hope it won't have cost me a 7. I cannot remember which question this was, probably 9, but we had to work out the bond angle of SF4. I got the shape right but I never learnt or came across bond angles for see saw shapes so I guessed 107. What did you guys get for that?

I said the same thing. 107 for one and <120 and<180 for the other one.both had a lone pair. What did you writr for the question were they asked about the covalent bond between hydrogen and carbon?

 

 

So the bond angles for the seesaw should be more than 180 so 186 because of the pair of lone electrons that has extra repulsion, less then 120, so 116 and exactly 90 so 186,116 and 90. I was blessed with this question as I wrote all of the shapes and bond angles on paper night before the exam and memorised I think that Pearson's HL book is great for learning bonding cuz in Study Guide they do not pay attention to shapes and bond angles. 

 

Damn, you are right

What did you guys get on question 7 I believe, on the PH for ammonia solution or something like that?

Edited May 16, 2015 by Klauu

[sam1996]

(TZ2) I'm super frustrated with the amount of silly errors I made in paper 2 (not reading the question properly, unit conversions etc.) I hope it won't have cost me a 7. I cannot remember which question this was, probably 9, but we had to work out the bond angle of SF4. I got the shape right but I never learnt or came across bond angles for see saw shapes so I guessed 107. What did you guys get for that?

I said the same thing. 107 for one and <120 and<180 for the other one.both had a lone pair. What did you writr for the question were they asked about the covalent bond between hydrogen and carbon?

 

So the bond angles for the seesaw should be more than 180 so 186 because of the pair of lone electrons that has extra repulsion, less then 120, so 116 and exactly 90 so 186,116 and 90. I was blessed with this question as I wrote all of the shapes and bond angles on paper night before the exam and memorised I think that Pearson's HL book is great for learning bonding cuz in Study Guide they do not pay attention to shapes and bond angles.

Damn, you are right

What did you guys get on question 7 I believe, on the PH for ammonia solution or something like that?

The bond angles were tough, for the see saw! I got a ph of around 11 I believe.

[2to10]

 

(TZ1) For paper 1, what was the answer to what would change the Kc value. I put C (increase in concentration) but I'm not sure.

There was another question where there was two arrows. It went something like hydrocarbon -- X -- CH3CH2NH2 and said find x? Does anyone remember it.

 

For paper 2, I remember doing 6 and 8 for section B.

 

I wasn't sure about the economic need for catalyst in the contact process on question 6? 

Left a whole pH question blank even though I knew the ph = pKa - [weak acid]/[base]

uh I put no change for that one. I thought Kc is only depended upon temperature. Since it was constant temp i think Kc remains the same. 

 

My bad. The question I was referring to was what affects k, the rate, not Kc. But I put no change for the Kc one as well!!

[sam1996]

I wish I could put my mind to rest about this but I cannot. Can any of you recall your answer or the question regarding which polymerisation process was not possible? In P1 TZ2

Edited May 16, 2015 by sam1996

[anotheribkid]

 

 

(TZ1) For paper 1, what was the answer to what would change the Kc value. I put C (increase in concentration) but I'm not sure.

There was another question where there was two arrows. It went something like hydrocarbon -- X -- CH3CH2NH2 and said find x? Does anyone remember it.

 

For paper 2, I remember doing 6 and 8 for section B.

 

I wasn't sure about the economic need for catalyst in the contact process on question 6? 

Left a whole pH question blank even though I knew the ph = pKa - [weak acid]/[base]

uh I put no change for that one. I thought Kc is only depended upon temperature. Since it was constant temp i think Kc remains the same. 

 

My bad. The question I was referring to was what affects k, the rate, not Kc. But I put no change for the Kc one as well!!

 

I thought that question was actually about Kc and how it would decrease, where one answer was a decrease in temperature - which would be correct. 

And the question with two arrows, I thought the answer was an alcohol - I don't remember what A was for the answer, B had added a Cl and an H which wouldn't have been possible with the bonding structure (there would be one extra H as the hydrocarbon was already saturated), C was the alcohol, and D was a halogenoalkane that ended with Cl2 which I don't think is possible (but it may be, I didn't study for organic at all before the test)

 

For paper 2, I also ended up doing questions 6 and 8! For the economic need, I said that it increases the rate of reaction - does not affect the yield but producing production speeds up

[2to10]

 

 

 

(TZ1) For paper 1, what was the answer to what would change the Kc value. I put C (increase in concentration) but I'm not sure.

There was another question where there was two arrows. It went something like hydrocarbon -- X -- CH3CH2NH2 and said find x? Does anyone remember it.

 

For paper 2, I remember doing 6 and 8 for section B.

 

I wasn't sure about the economic need for catalyst in the contact process on question 6? 

Left a whole pH question blank even though I knew the ph = pKa - [weak acid]/[base]

uh I put no change for that one. I thought Kc is only depended upon temperature. Since it was constant temp i think Kc remains the same. 

 

My bad. The question I was referring to was what affects k, the rate, not Kc. But I put no change for the Kc one as well!!

 

I thought that question was actually about Kc and how it would decrease, where one answer was a decrease in temperature - which would be correct. 

And the question with two arrows, I thought the answer was an alcohol - I don't remember what A was for the answer, B had added a Cl and an H which wouldn't have been possible with the bonding structure (there would be one extra H as the hydrocarbon was already saturated), C was the alcohol, and D was a halogenoalkane that ended with Cl2 which I don't think is possible (but it may be, I didn't study for organic at all before the test)

 

For paper 2, I also ended up doing questions 6 and 8! For the economic need, I said that it increases the rate of reaction - does not affect the yield but producing production speeds up

 

Yeah, but there was also a question that said rate = k [c]  and then it asked what would affect the value of k. That's the question I'm referring too. I guess I got "X" question wrong because i put B, with the one Cl.

Yeah, I said the catalyst increases the rate of reaction as well, but I wasn't sure if that completely answered the question, so I said the increased rate of reaction allows for the preservation of time and resources.

Since you did eight, do you remember what you got for the first pH question. I think it said find the pH of CH3COOH?

Edited May 17, 2015 by 2to10

[J9726gp]

Does anyone now any other sites or a google document where people post questions that they remembered?

[Runner22909]

Btw, does anyone know whether the ib scans only the boxes or the whole page for paper 2? I might have written some of my answers outside the boxes.

[simpletime]

Btw, does anyone know whether the ib scans only the boxes or the whole page for paper 2? I might have written some of my answers outside the boxes.

only the boxes, unless you have stated in your answer that you are writing on another paper. 

[ketone]

 

Btw, does anyone know whether the ib scans only the boxes or the whole page for paper 2? I might have written some of my answers outside the boxes.

only the boxes, unless you have stated in your answer that you are writing on another paper. 

 

Do they scan the whole box? or only the lines in the box , because there are space outside the line but in the box

[ketone]

I wish I could put my mind to rest about this but I cannot. Can any of you recall your answer or the question regarding which polymerisation process was not possible? In P1 TZ2

Both molecule requires two functional group on each side. -COOH-R-HOOC and -OH-R-HO-

[lolatlife]

I think that the curve is going to be soo high for p2 and p3 and in p1 if you get like 34/40 its a 7. Although I don't want high grade boundaries for p2 I have silly mistakes.

Edited May 17, 2015 by lolatlife

[BlueWizard]

Hey guys, what did you get for the 3rd question in P1? it was the PV=nRT thing 

and another question towards the end: the pH change when NaOH is added to water.. was the pH 10 or 12 at the end??

[ketone]

Hey guys, what did you get for the 3rd question in P1? it was the PV=nRT thing 

and another question towards the end: the pH change when NaOH is added to water.. was the pH 10 or 12 at the end??

I wrote ph 10 but pure guessing. NaOH should be at ph 14, and after adding 1dm3 of water, I expect it to fall about 4 pH. 

 

Btw for question 3, I wrote the one with 10^3 but it now regret caz i know the ans shud be the one with 10^-3 because of conversion of units.

 

What did you for question 2?

Edited May 17, 2015 by ketone

[BlueWizard]

 

Hey guys, what did you get for the 3rd question in P1? it was the PV=nRT thing 

and another question towards the end: the pH change when NaOH is added to water.. was the pH 10 or 12 at the end??

I wrote ph 10 but pure guessing. NaOH should be at ph 14, and after adding 1dm3 of water, I expect it to fall about 4 pH. 

 

Btw for question 3, I wrote the one with 10^3 but it now regret caz i know the ans shud be the one with 10^-3 because of conversion of units.

 

What did you for question 2?

 

I was hesitating and wrote pH 12 it's wrong i know...

 

uhmm.. i don't remember really, but i narrowed it down to the Mr at the top (44) which was answer B or Mr at the bottom which was answer C I think? and I chose the latter option.. i'm still baffled by this question.. 

[ketone]

 

 

Hey guys, what did you get for the 3rd question in P1? it was the PV=nRT thing 

and another question towards the end: the pH change when NaOH is added to water.. was the pH 10 or 12 at the end??

I wrote ph 10 but pure guessing. NaOH should be at ph 14, and after adding 1dm3 of water, I expect it to fall about 4 pH. 

 

Btw for question 3, I wrote the one with 10^3 but it now regret caz i know the ans shud be the one with 10^-3 because of conversion of units.

 

What did you for question 2?

 

I was hesitating and wrote pH 12 it's wrong i know...

 

uhmm.. i don't remember really, but i narrowed it down to the Mr at the top (44) which was answer B or Mr at the bottom which was answer C I think? and I chose the latter option.. i'm still baffled by this question.. 

 

I have no idea and I choose B purely because B wasnt chosen many times 

[simpletime]

 

 

Btw, does anyone know whether the ib scans only the boxes or the whole page for paper 2? I might have written some of my answers outside the boxes.

only the boxes, unless you have stated in your answer that you are writing on another paper. 

 

Do they scan the whole box? or only the lines in the box , because there are space outside the line but in the box

 

they scan the box, that includes the spaces outside the lines

[Ossih]

 

I wish I could put my mind to rest about this but I cannot. Can any of you recall your answer or the question regarding which polymerisation process was not possible? In P1 TZ2

Both molecule requires two functional group on each side. -COOH-R-HOOC and -OH-R-HO-

 

That was the II statement but III was right too with H2N - R - COOH and another H2N - R - COOH because they have two functional groups (and these are in fact amino acids that condense to form long polymers that we call proteins Its covered more in Option B)

 

so it was the option that had both II and III 

[sam1996]

I wish I could put my mind to rest about this but I cannot. Can any of you recall your answer or the question regarding which polymerisation process was not possible? In P1 TZ2

Both molecule requires two functional group on each side. -COOH-R-HOOC and -OH-R-HO-

That was the II statement but III was right too with H2N - R - COOH and another H2N - R - COOH because they have two functional groups (and these are in fact amino acids that condense to form long polymers that we call proteins Its covered more in Option B)

 

so it was the option that had both II and III

YES! Thank you for that. I need every mark possible after my tragic paper 2!

[sam1996]

Last one I'll bother you with, the question regarding which combination would form a buffer? I picked the one with weak acid 20cm^3 and strong base 10cm^3, or vice versa if it was an alkaline buffer.