Chemistry: Post your doubts here!

[qwertypoiu]

Is So3 connected via PD PD forces or Van Der waals?Shouldnt it be PD PD Due to difference in e-vity of S and O?Or is SO3 symmetrical?.
Also are large scale uses of halogenoalkanes,naoh and other such compounds included.What are included.

Also when HCL is dissolved in water is the bonding changed to form ions of H30 and Cl or due to hydrogen bonds being formed?

Metanoia
The Sarcastic Retard

SO3 is symmetrical, it wouldn't have permanent dipole attraction.

 

[ashcull14]

 

[asadalam]

View attachment 52888

Look closely. Its the CH2OH group that is oxidised not the carbon youvd highlighted.so it can be oxidised

 

[qwertypoiu]

View attachment 52888

This is actually a primary alcohol.
-CH2OH means primary.
OH group is attached to a carbon atom that has two hydrogen atoms bonded to it.
Or, the OH group is attached to a carbon atom that is only bonded to one other carbon atom.

 

[Lola_sweet]

Delta H = Bonds broken - Bonds formed

You're already told the value of Delta H, so use that as a starting point. Now work out the total energy for bonds broken and the total energy for bonds formed.
Bonds broken:-

1 x C=C
4 x C-H
1 x H-F

Bonds formed :-

1 x C-F
5 x C-H
1 x C-C

Bonds broken = 610 + 4(410) + 562 = 2812 kJmol-1
Bonds formed = X + 5(410) + 350 = 2400 + X kJmol-1

X is the bond energy of C-F which we are going to find.

-73 kJmol-1 = 2812 - ( 2400 + X )
-73 = 2812 - 2400 - X
X = 2812 - 2400 + 73
X = 485 kJmol-1

Hope that helped!

THANK U SOOO MUCH!!!!!!!!!!

 

[The Sarcastic Retard]

Is So3 connected via PD PD forces or Van Der waals?Shouldnt it be PD PD Due to difference in e-vity of S and O?Or is SO3 symmetrical?.
Also are large scale uses of halogenoalkanes,naoh and other such compounds included.What are included.

Also when HCL is dissolved in water is the bonding changed to form ions of H30 and Cl or due to hydrogen bonds being formed?

Metanoia
The Sarcastic Retard

•It is a planar molecule with the oxygens spaced at 120 degrees around the central sulfur. Consequently it is perfectly symmetrical and has no dipole moment.
•Included in what, I dont get you. Sorry.
•Look at the image attached below:

 

[robinhoodmustafa]

Here's the mark scheme: http://freeexampapers.com/A-Level/Chemistry/CIE/2012-Jun/9701_s12_ms_22.pdf

My doubt: How do I figure out how many lone pairs are present?

Draw the dot and cross of that compound. Un bonded pairs of electrons on the atom denotes the lone pair present

 

[princess Anu]

what do these terms imply;
monohydric
dibasic

 

[princess Anu]

can somebody explain how do we name this compound ;
(Ch3)2CBrCH3

 

[princess Anu]

can somebody post 2001 J/N question papers & marking scheme ?? pls

 

[princess Anu]

How do shell/ subshell/ orbital mainly differ from each other??

 

[Metanoia]

whats the reason for oxides getting more acidic as we move across the period

The short answer to this is to realize that the types of bonding changes from ionic to covalent across the Period.

The more in-depth answer is found in the paragraph below.



From Understanding Advanced Physical Inorganic Chemistry
http://www.worldscientific.com/worldscibooks/10.1142/7833

 

[qwertypoiu]

what does these terms imply;
monohydric
dibasic

A monohydric alcohol has only one hydroxyl group. (OH)
An example of such an alcohol would be ethanol, CH3CH2OH.

A dibasic acid has two hydrogen atoms that can ionise and form H+ ions.
An example would be H2SO4.

A dibasic salt is one that was formed by replacement of two hydrogen atoms from the acid. An example would be Na2HPO4.
This was obviously formed from H3PO4.

Please note that I just looked these words up, if anyone finds mistakes in what I've written please correct me.

 

[qwertypoiu]

can somebody explain how do we name this compound ;
(Ch3)2CBrCH3

2-bromo-2-methylpropane

The longest chain has 3 carbons.
The second carbon has a bromine atom and a methyl group attached. Perhaps it's easier to understand if the compound is written like this:
CH3C(CH3)BrCH3

 

[princess Anu]

2-bromo-2-methylpropane

The longest chain has 3 carbons.
The second carbon has a bromine atom and a methyl group attached. Perhaps it's easier to understand if the compound is written like this:
CH3C(CH3)BrCH3

but why are we not taking the functional group ie Br in the longest chain? isn't it a rule to always include the functional group of a compound in the longest chain? but here we're actually taking br as a branch :/ whyy

 

[qwertypoiu]

How do shell/ subshell/ orbital mainly differ from each other??

Shell is the principal quantum number.
It's like the first shell, second shell, third shell we learnt in igs.
Within shells, there are subshells.
So 1s is a subshell, 2p is a subshell, 4f, etc.
Within these subshells are orbitals. Orbitals allow two electrons within themselves, and have different orientations. We need to know that the p subshell can contain up to 6 electrons, because it has 3 orbitals within it, with different orientation:
Px, Py. Pz...
each of these contain 2 electrons, so in total 6 in a p subshell.

 

[qwertypoiu]

but why are we not taking the functional group ie Br in the longest chain? isn't it a rule to always include the functional group of a compound in the longest chain? but here we're actually taking br as a branch :/ whyy

Functional groups are always side chains. We name compounds based on longest carbon chain.

EDIT: IT'S NOT! See below.

 

[Metanoia]

Functional groups are always side chains. We name compounds based on longest carbon chain.

I'll correct this. The longest chain must contain the principal functional group.

http://www.masterorganicchemistry.c...functional-group-priorities-for-nomenclature/

 

[qwertypoiu]

I'll correct this. The longest chain must contain the principal functional group. Halogens are of lower ranking than alkanes, so halogens are considered as prefixes.

http://www.masterorganicchemistry.c...functional-group-priorities-for-nomenclature/

Thank you.

 

[Fiery987]

M/J 2010 P22
Q#5 b (iii)
I wrote Al2O3 as it is found in pumice.
How is the answer only SiO2??