Chemistry: Post your doubts here!

[AbbbbY]

Why won't SO2 wont show up?

How do you test for SO2 gas? Why would it show up if you're never taught how to test for it -_-

Ok looks like I was mistaken. I just confirmed the CIE amendment to the syllabus for P3.

It was the Pb2+ ion that they've removed not SO2. So, K2Cr2O7 will very much be on the reagents bench and you'll have to test for it by soaking the white strips of filter paper. If it turns from orange to green, voila.

 

[AbbbbY]

yeah... at least i think it will be fine.
bcz seriously how wud we know if the examiner will write them on the left or the right side. i wudve written it the more standard way : on the right side.

In exam you're supposed to always electrons in terms of addition, not subtraction, even though examiners will often ask you in terms of electrons subtracted.

X + e -> X
never
X - e -> X

 

[Namehere]

In exam you're supposed to always electrons in terms of addition, not subtraction, even though examiners will often ask you in terms of electrons subtracted.

X + e -> X
never
X - e -> X

If what I understand is correct, there is no difference on writing an electron as being added (onto one side of the equation) or subtracted (from the other side of the equation), so any way will be correct in the exam.

 

[AbbbbY]

Does anyone here have any diagram of electrophoresis? I mean an easy one because Marking schemes shows 3D diagrams. Thank You Suchal Riaz AbbbbY Namehere

This is what I make.

 

[daredevil]

Does anyone here have any diagram of electrophoresis? I mean an easy one because Marking schemes shows 3D diagrams. Thank You Suchal Riaz AbbbbY Namehere

the one AbbbbY drew was good too but they have given the diagram for that apparatus in the application booklet too :

 

[Rutzaba]

okay now i'm confused O_O

Rutzaba A star syed1995
u guys ... any thots? :`)

dint have chem

 

[A star]

This is what I make.

this made me feel so much better that some one daws as much worse as I do

 

[itallion stallion]

In exam you're supposed to always electrons in terms of addition, not subtraction, even though examiners will often ask you in terms of electrons subtracted.

X + e -> X
never
X - e -> X

Can u plz solve the electrode potential posted above,there Is a confusion in it.thanks
Bro still waiting for the p5.

 

[AbbbbY]

this made me feel so much better that some one daws as much worse as I do

Hahahh. This is one of my better drawings

Always sucked at drawings and diagrams and always will. This is why I loathe P5. All my diagrams are so funny it's actually amusing lol

 

[A star]

Hahahh. This is one of my better drawing

Always sucked at drawings and diagrams and always will. This is why I loathe P5. All my diagrams are so funny it's actually amusing lol

haha my long lost brother/sister . same here XD

 

[Abdulaziz T]

Guys if the question says draw the structure in organic chemistry , do we draw structural, displayed or skeletal diagrams ??

 

[Farez]

Guys if the question says draw the structure in organic chemistry , do we draw structural, displayed or skeletal diagrams ??

Unless they specifically ask for a particular structure diagram, any correct representation of the structure will be accepted.

 

[Abdulaziz T]

Unless they specifically ask for a particular structure diagram, any correct representation of the structure will be accepted.

Thanks a lot

 

[hope4thebest]

This is what I make.

Thank You so much! But once I made a similar diagram and my teacher pointed out that this is close to electrolysis, draw it as it is in marking scheme

 

[Farez]

Thank You so much! But once I made a similar diagram and my teacher pointed out that this is close to electrolysis, draw it as it is in marking scheme

Teachers usually treat the mark scheme as the Bible or something lol. No need to draw it exactly as the mark scheme. Just make sure your diagram includes the relevant points quoted in the mark scheme, as those are what was marked :

• power supply
• electrolyte + filter paper
• buffer
• acid mixture central

So this diagram should suffice:

 

[unique111]

Does anyone have the 'Example Candidate Response Booklet' for chem?

 

[itallion stallion]

Can someone plz explain this
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_43.pdf
Question no 6 part F.thanks!

 

[A star]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s13_qp_41.pdf Q2a(iv)

 

[Farez]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_qp_41.pdf Q2a(iv)

1. Pick a point on one of the graphs
2. Draw a tangent line and calculate the gradient of that line. This is the rate.
3. Take the appropriate concentrations and place the values of the rate and concentrations in the rate equation
4. Solve for k.

 

[A star]

1. Pick a point on one of the graphs
2. Draw a tangent line and calculate the gradient of that line. This is the rate.
3. Take the appropriate concentrations and place the values of the rate and concentrations in the rate equation
4. Solve for k.

thanks alot budy (Y) .