Chemistry: Post your doubts here!

[Dark Destination]

not u

Okay

 

[Iridescent]

Hydrogen bonding cannot form between H and Cl. The difference in electronegativity isn't that high to allow a very strong hydrogen bond to form. In addition to that, HCl is non-polar; it has induced dipole forces of attraction.

HCl is a polar molecules. H has a partial positive charge while Cl has a partial negative charge since chlorine is highly electronegative compared to hydrogen. The force between HCl molecules is permanent dipole attraction. Not induced dipole forces.

 

[Awesome12]

master of chem n u asked me tht quest in inbox? u were teasin me?

I didnt go to school last week, which is why I didnt get the hand of the entire mass thing, like whose mass should I use in the formula.

 

[RoOkaYya G]

I didnt go to school last week, which is why I didnt get the hand of the entire mass thing, like whose mass should I use in the formula.

oh ok np

 

[Muskan Achhpilia]

Hey,
Can anyone please help me out with the following question-:






The b) (ii) part is doubt^

I don't get how to draw the structure when the diol with carboxylic acid will react with the carboxylic acid...

The question is from summer 2009 first variant paper 2 question 4 b) (ii)


Thanks a tonne!!

 

[Bba321]

Hi
Can anyone tell me if we write 4s and then 3d in group 4 elements like Ge,Sn and Pb or do we write 3d or the other way?

Confused please help
Thanks

 

[Fatima Naeem]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_12.pdf

Can someone please solve question 10? I don't get why it is B. :/

 

[3l_general]

October 2012 , paper 13 .
Question 5
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/

 

[Snowysangel]

Could someone please explain the reaction between iodine and thiosulfate ions to me?

 

[princess Anu]

Q29

 

[Paris Palmer]

HCl is a polar molecules. H has a partial positive charge while Cl has a partial negative charge since chlorine is highly electronegative compared to hydrogen. The force between HCl molecules is permanent dipole attraction. Not induced dipole forces.

Why is the Ionic Radius of transition elements invariant?

 

[muhammad dabeer]

hi guys,
i want a lvl chem past papers of 1996 if any1 have it plz upload it soon.
according to my knowledge kgs library contains it.

 

[Paris Palmer]

hi guys,
i want a lvl chem past papers of 1996 if any1 have it plz upload it soon.
according to my knowledge kgs library contains it.

Can someone please send me a link to download Chem A Levels pastpapers of June 2014?

 

[Maqb0ol]

Can someone please send me a link to download Chem A Levels pastpapers of June 2014?

Here it is "http://maxpapers.com/category/qualifications/international/cambridge/a-level/a-level-chemistry-9701/"

 

[princess Anu]

Solution please?!

 

[Awesome12]

How is it C??

 

[princess Anu]

How is it C??

View attachment 49720

The ratio of volume of gases is the ratio of their moles
So 1:3:1:1:1 is the ratio shown by the equation but the ratio given is 1:6
therefore 30cm of O2 will be used leaving the excess (30cm)
and we get 10 cm of CO2, h20 nd SO2 makes a total of 6o. But since the mixture is cooled, h20 will convert into water and so the remaining volume will be 50.

 

[Awesome12]

The ratio of volume of gases is the ratio of their moles
So 1:3:1:1:1 is the ratio shown by the equation but the ratio given is 1:6
therefore 30cm of O2 will be used leaving the excess (30cm)
and we get 10 cm of CO2, h20 nd SO2 makes a total of 6o. But since the mixture is cooled, h20 will convert into water and so the remaining volume will be 50.

Thanks.

 

[Awesome12]

Why is it B?

 

[princess Anu]

Why is it B?

View attachment 49733

The dipoles in A C D cancel out but not in B.
Remember, Trigonal planar shaped molecules can cancel dipoles if all the bonds made are polar, like in C.