Chemistry: Post your doubts here!

[hmlahori]

can someone explain how NO2 is polar?
the electronegativities of N and O are different so the bonds will be polar but wont the dipoles cancel each other out and the overall compound becomes nonpolar.

 

[étudiante]

can someone explain how NO2 is polar?
the electronegativities of N and O are different so the bonds will be polar but wont the dipoles cancel each other out and the overall compound becomes nonpolar.

the bond angle is not 180 (because of the lone pair on nitrogen) thus it will be cancelled to some extent but not completely and will overall be polar

 

[hmlahori]

the bond angle is not 180 (because of the lone pair on nitrogen) thus it will be cancelled to some extent but not completely and will overall be polar

does the shape of a molecule affect the overall polarity of a compound to a large extent then?

 

[étudiante]

does the shape of a molecule affect the overall polarity of a compound to a large extent then?

yes! dipoles are vectors so if u want them to completely cancel, u need to take into account direction as well... (i.e. shape)

 

[hmlahori]

yes! dipoles are vectors so if u want them to completely cancel, u need to take into account direction as well... (i.e. shape)

Ok rite yes i just drew the NO2 molecule and i get what you mean. Its nitrogen part will be partial positive and two oxygen atoms partial negative so it is polar just like in H2O and as they are both bent so dipoles wont completely cancel out. Thanks a lot!

 

[étudiante]

Ok rite yes i just drew the NO2 molecule and i get what you mean. Its nitrogen part will be partial positive and two oxygen atoms partial negative so it is polar just like in H2O and as they are both bent so dipoles wont completely cancel out. Thanks a lot!

exactly! ur welcome
except that the bond angle will be different frm H2O its da same concept

 

[hmlahori]

exactly! ur welcome
except that the bond angle will be different frm H2O its da same concept

yes yes i know because there are 2 lone pairs in H2O and one in NO2. but you know i never really considered the shape but now these questions will be easier to solve thanks again!

 

[saudha]

Which ion is most polarising?
A Al3+
B Ba2+
C Mg2+
D Na+

wht do u mean by pol arising?

 

[étudiante]

yes yes i know because there are 2 lone pairs in H2O and one in NO2. but you know i never really considered the shape but now these questions will be easier to solve thanks again!

yep! ^_^
ur so welcum... just remember me in ur prayers pls

 

[1357913579]

can you guys please also clear my doubts which i posted in the AS chemistry forum i would be very thankfull of you please help

 

[étudiante]

Which ion is most polarising?
A Al3+
B Ba2+
C Mg2+
D Na+

wht do u mean by pol arising?

the one dat can distort the charge cloud of the anion the most....
it will be the one with the greatest charge denstiy (i.e. smallest radius and highest charge)

 

[étudiante]

can you guys please also clear my doubts which i posted in the AS chemistry forum i would be very thankfull of you please help

can u give me the link please? i'll try to... its a good revision

 

[angelgirl:)]

How does concentrated sulfuric acid behave when it reacts with sodium chloride?
A as an acid only
B as an acid and oxidising agent
C as an oxidising agent only
D as a reducing agent only

 

[TheMan123]

An aqueous solution was prepared containing 1.0mol of AgNO3 and 1.0mol of FeSO4 in 1.00 dm3
of water. When equilibrium was established, there was 0.44mol of Ag+(aq) in the mixture.
Ag+(aq) + Fe2+(aq) --> Ag(s) + Fe3+(aq)

What is Kc?

A. 0.35 B. 0.62 C. 1.62 D. 2.89

I got C as my answer but the correct one is D, can anyone explain how to get D?

Edit: Oops I missed out the question! I just added it

 

[TheMan123]

How does concentrated sulfuric acid behave when it reacts with sodium chloride?
A as an acid only
B as an acid and oxidising agent
C as an oxidising agent only
D as a reducing agent only

answer is A. Here's a good link to explain why: http://www.chemguide.co.uk/inorganic/group7/halideions.html

Also check out my question if you can help me

 

[saudha]

An aqueous solution was prepared containing 1.0mol of AgNO3 and 1.0mol of FeSO4 in 1.00 dm3
of water. When equilibrium was established, there was 0.44mol of Ag+(aq) in the mixture.
Ag+(aq) + Fe2+(aq) --> Ag(s) + Fe3+(aq)

A. 0.35 B. 0.62 C. 1.62 D. 2.89

I got C as my answer but the correct one is D, can anyone explain how to get D?

wht is the Q

 

[TheMan123]

wht is the Q

I don't understand? Do you mean what is the question? If you mean that, you just replied to it

EDIT: Ooops sorry!!! Here's the question:
What is Kc?

 

[1357913579]

can u give me the link please? i'll try to... its a good revision

please some one help as soon as possible
oct/nov 2010 second variant numer-7,18,31,34,36. soory for so much question but what can i do the paper semmed hard for me got these mistakes and unfortunately coudnt resolve any of my mistakes

thanks for helping all xpc members
http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
this was what i posted there.
thanks for helping.

 

[étudiante]

please some one help as soon as possible
oct/nov 2010 second variant numer-7,18,31,34,36. soory for so much question but what can i do the paper semmed hard for me got these mistakes and unfortunately coudnt resolve any of my mistakes

thanks for helping all xpc members
http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
this was what i posted there.
thanks for helping.

its alright
can u please give me a direct link to the paper itself cuz i cant find it atm... den i'll try 2 solve dem

 

[TheMan123]

I asked this question already, but just thought I post it again since we're on a new page.

An aqueous solution was prepared containing 1.0mol of AgNO3 and 1.0mol of FeSO4 in 1.00 dm3
of water. When equilibrium was established, there was 0.44mol of Ag+(aq) in the mixture.
Ag+(aq) + Fe2+(aq) --> Ag(s) + Fe3+(aq)

What is Kc?

A. 0.35 B. 0.62 C. 1.62 D. 2.89

I got C as my answer but the correct one is D, can anyone explain how to get D?