Chemistry: Post your doubts here!

[A*****]

Any guess paper or prediction for tomorrow practical chemistry P33?

34*

 

[shevanka]

34*

please email me if you find something - [email protected]

 

[aloo Kha]

paper 34: will there really be organic in no 3?

 

[abbas haider]

Can Anyone Tell what's the accuracy of Burette ,pippete ,meauring cylinder and Thermometer? (how many d.p would i write if i measure from each one of these?)

 

[ghazanfar1234565]

please can any one tell about the ions of p34

 

[Kanekii]

Need help with this.
For the first one i know its a reaction pathway of SN1 reaction but why can it not be A or D since they don't have graphs like that i guess

 

[shevanka]

please can any one tell about the ions of p34

please can any one tell about the ions of p34

i think sulphate,copper and iron 2

 

[ba-lock-ey]

Can Anyone Tell what's the accuracy of Burette ,pippete ,meauring cylinder and Thermometer? (how many d.p would i write if i measure from each one of these?)

Thermometer to whole number like 50.0 or to .5 like 64.5
MAKE SURE YOU PUT TO ONE DP, and the only decimals are .0 and .5

Burette 0.05 for each reading.

 

[Mts.99]

Uncertainty in pipette is 0.06?

 

[ba-lock-ey]

Uncertainty in pipette is 0.06?

What type of pipette? 25?

 

[ba-lock-ey]

34*

Practice. I don't think it's right to ask this since the admin of Xtremepapers check the forums and ban people for discussing such questions. Good tip: memorize cation and anion rxns or at least learn to identify what the question is asking so you don't have to waste time going through the last sheet.

 

[Mts.99]

What type of pipette? 25?

yes

 

[angryrider_56]

"Also, study the reaction of kmno4 with glucose from the net. If any reaction equation is available please study equation as well.
Expected practical is organic based. Please study fehlings tollens and iodoform test with equations."
-Got this from a friend...Good luck bois

 

[A*****]

View attachment 63722 View attachment 63723 Need help with this.
For the first one i know its a reaction pathway of SN1 reaction but why can it not be A or D since they don't have graphs like that i guess

In 28 A, an intermediate is formed with O- and so the reaction is a 2 step process
Similarly with D, first 1 Br attaches and a carbocation is formed and so it is also a 2 step pathway

 

[A*****]

View attachment 63722 View attachment 63723 Need help with this.
For the first one i know its a reaction pathway of SN1 reaction but why can it not be A or D since they don't have graphs like that i guess

For 32, O has 2 unpaired p electrons and for the Cl+, u need to understand that Cl atom has 5 p electrons, 2 paired and 1 unpaired...when Cl+ is formed, the electron removed is from the full p orbital, leaving 2 unpaired p electrons behind
Once u understand this, u can easily work out 2 and 3

 

[A*****]

Someone plz explain these...also plz explain why the other options are wrong

 

[innovative_1]

View attachment 63726 View attachment 63727

Someone plz explain these...also plz explain why the other options are wrong

 

[abbas haider]

View attachment 63726 View attachment 63727

Someone plz explain these...also plz explain why the other options are wrong

4 B .... in Al2Cl6 1 Al atom has 4 bonds thus 8 electrons .....In CH3+ = 4 electron of carbon naturally 3 electron given by H -1 due to + chage so 4+3-1 = 6 ....In Cl2O ..(just like H20) oxygen in g6 + 2 bonded electrons = 8 ....In H2ClC. C radical (1 electron un paired) means carbon is bonded to 3 atoms and C-Cl means Cl has 8 ....

 

[innovative_1]

View attachment 63726 View attachment 63727

Someone plz explain these...also plz explain why the other options are wrong

 

[A*****]

4 B .... in Al2Cl6 1 Al atom has 4 bonds thus 8 electrons .....In CH3+ = 4 electron of carbon naturally 3 electron given by H -1 due to + chage so 4+3-1 = 6 ....In Cl2O ..(just like H20) oxygen in g6 + 2 bonded electrons = 8 ....In H2ClC. C radical (1 electron un paired) means carbon is bonded to 3 atoms and C-Cl means Cl has 8 ....

Thankssss