Chemistry: Post your doubts here!

[princess Anu]

Yes, you can simplify it in that way.



Answer is B.

thankyou
Q: whats the difference between methylbenzene and benzene reactions? For As level only
btw, see A and B give these products and none of them seems to be like the desired one to me

 

[Metanoia]

thankyou
Q: whats the difference between methylbenzene and benzene reactions? For As level only
btw, see A and B give these products and none of them seems to be like the desired one to me

There are errors in your drawings (which is why it is important for me to see them rather then provide the answer straightaway).


This will explain why B is the answer.

 

[MafaldaC]

Form an equation between the Kc and the respective concentrations,then solve for the concentration of HI
View attachment 50295

Thank you again!! Can you help me with another one please?

May june 2014 P12 Q4
Hydrogen and carbon dioxide gases are mixed in equal molar amounts at 800 K. A reversible

reaction takes place.

H2(g) + CO2(g) H2O(g) + CO(g)

At equilibrium, the partial pressures of H2 and CO2 are both 10.0 kPa. Kp is 0.288 at 800 K.

What is the partial pressure of CO in the equilibrium mixture?

A 5.37 kPa B 18.6 kPa C 28.8 kPa D 347 kPa

5

 

[Metanoia]

Thank you again!! Can you help me with another one please?

May june 2014 P12 Q4
Hydrogen and carbon dioxide gases are mixed in equal molar amounts at 800 K. A reversible

reaction takes place.

H2(g) + CO2(g) H2O(g) + CO(g)

At equilibrium, the partial pressures of H2 and CO2 are both 10.0 kPa. Kp is 0.288 at 800 K.

What is the partial pressure of CO in the equilibrium mixture?

A 5.37 kPa B 18.6 kPa C 28.8 kPa D 347 kPa

5

Try using the method shown in the previous question and express the Kp in terms of the equilibrium concentrations. Let the unknown pressure of CO be x.
Post what you have after that and I'll guide you from there if you're still stuck.

Edited: Changed "moles of CO" to "pressure of CO"

 

[MafaldaC]

Try using the method shown in the previous question and express the Kp in terms of the equilibrium concentrations. Let the unknown moles of CO be x.
Post what you have after that and I'll guide you from there if you're still stuck.

So
20/0.288 = p(H20) + p (CO)
and then i don't understand, it doesn't give me nothing for h20 and is the p(co) 1/4 x Tp? what is the Tp??

 

[Metanoia]

So
20/0.288 = p(H20) + p (CO)
and then i don't understand, it doesn't give me nothing for h20 and is the p(co) 1/4 x Tp? what is the Tp??

I made a typo in the previous message, the unknown x is for partial pressure (not moles) of CO.



solve for x...

 

[MafaldaC]

I made a typo in the previous message, the unknown x is for partial pressure (not moles) of CO.

View attachment 50311

solve for x...

Omgg im so dumb!!! now i know what i was doing wrong ahahahah thanksss

 

[princess Anu]

Right thankyou
btw can u tell me the difference in the reaction of benzene and methyl benzene with br2

There are errors in your drawings (which is why it is important for me to see them rather then provide the answer straightaway).
View attachment 50301

This will explain why B is the answer.
View attachment 50302

 

[princess Anu]

how to decide whether 3:1 or 1:1?

 

[princess Anu]

Why is 1 right ?

 

[princess Anu]

۔

 

[Sweet Guy]

I need Suggestions about Chemistry Paper 4 Question Pattern

 

[princess Anu]

why is electron affinity of Chlorine less than that for Fluorine

 

[Muskan Achhpilia]

Hi,
Can anyone help me out with the following questionsThe marking scheme is also given.


Thank you,

 

[savera]

Right thankyou
btw can u tell me the difference in the reaction of benzene and methyl benzene with br2

The reaction with bromine

The reaction between benzene and bromine takes place with the help of a catalyst such as AlBr3 (if you are reacting with Cl2 then the catalyst will be AlCl3)

Methyl groups are 2,4-directing, which means that incoming groups will tend to go into the 2 or 4 positions on the ring.

OH and CH3 are electron releasing (electron withdrawing) groups, this means that they are 2 ,4 directing group. As in the above diagram the Br2 is in excess so it will take all 3 positions : 2,4,6. If in limited quantity then it will occupy only 2 position.

See the Untitled.png which i have attached. Once you have gone through it you wont have any problem regarding positioning of atoms/molecules e.g Br2 etc

Hope this helps.

 

[danial 234]

why is electron affinity of Chlorine less than that for Fluorine

radius of chlorine is greater than that of flourine. so the force exerted by chlorine nucleus on the electron is less than that exerted by a flourine nucleus

 

[Mahnoorfatima]

Qp 13 ON 12, question number 10 anyone?

 

[Mahnoorfatima]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf question 22??

 

[Dark Destination]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf question 22??

You just have to look at the values of bond energies from the data booklet and see which one is the lowest..

 

[princess Anu]

please explain...