Chemistry: Post your doubts here!

[Aina]

Guyzzz I need help for 7 d part
9701/42/O/N/13

 

[Farhad221]

Guys in the paper will we have to explain sp sp2 and sp3 hybridization?

 

[nehaoscar]

Guys in the paper will we have to explain sp sp2 and sp3 hybridization?

No - hybridization is not directly in the syllabus but you need to roughly know about it

 

[Abdul Hanan]

Guys in the paper will we have to explain sp sp2 and sp3 hybridization?

in AS don't worry about it.

 

[Metanoia]

a

I think you didn't understand my question

in ans to this I wrote because Hydrogen bonds donot form between ethoxyethane and H2O
but the Ms says
hydrogen bonds cannot form btween Ethoxyethane molecules :/

Is this an A level question and ms? Can post whole marking scheme here?

 

[Studydayandnight]

How do we do (b) part (ii)???

 

[nehaoscar]

http://freeexampapers.com/A-Level/Chemistry/CIE/2011-Jun/9701_s11_qp_21.pdf

Q 5 - b - i
Why is it electrophillic addition?
Cl has a negative charge right?
Shouldn't it be nucleophilic?

Can Anybody Find Me ... Somebody Somebody Somebody to Answer ^^

 

[Metanoia]

The hydrogens are attached to the carbons
For hydrogen bonding, you need a H attached to a F,O or N

a

I think you didn't understand my question

in ans to this I wrote because Hydrogen bonds donot form between ethoxyethane and H2O
but the Ms says
hydrogen bonds cannot form btween Ethoxyethane molecules :/

The hydrogens are attached to the carbons
For hydrogen bonding, you need a H attached to a F,O or N

This is a common misconception by A level students. For hydrogen bonding, you need a hydrogen bond acceptor and a hydrogen bond donor.

For a hydrogen bond donor, you need a H joined to N, O, or F.
For a hydrogen bond acceptor, you need lone pairs on N, O, or F (there is no need for it to have a H atom directly joined).

 

[nehaoscar]

a

I think you didn't understand my question

in ans to this I wrote because Hydrogen bonds donot form between ethoxyethane and H2O
but the Ms says
hydrogen bonds cannot form btween Ethoxyethane molecules :/

Your answer is kinda correct except change the donot to cannot because it is not possible for them to form H-bonds as it isn't attache to a F,O or N

 

[Metanoia]

http://freeexampapers.com/A-Level/Chemistry/CIE/2011-Jun/9701_s11_qp_21.pdf

Q 5 - b - i
Why is it electrophillic addition?
Cl has a negative charge right?
Shouldn't it be nucleophilic?

It is not Cl- that reacts with the alkene in the first step. Don't forget that alkenes are electron rich, they will attract ELECTROPHILES.

Replace the Br-Br with Cl-Cl for the diagrams below.

 

[Mahnoorfatima]

Can someone please explain how alkanes are polymerised. I forgot. :/. And what are the conditions. For eg polymerisation of C3H6 and showing 2 repeat units. Plus do we need to know how cracking occurs like long chain hydrocarbons and short chain hydrocarbon formation?

 

[nehaoscar]

It is not Cl- that reacts with the alkene in the first step. Don't forget that alkenes are electron rich, they will attract ELECTROPHILES.

Replace the Br-Br with Cl-Cl for the diagrams below.

View attachment 53074

Oh right! Thankyou so much! So during reactions, to determine whether it is nucleophilic or electrophilic, do we always use the first reagent that reacts?

 

[BhaiArshad]

Can someone please explain how alkanes are polymerised. I forgot. :/. And what are the conditions. For eg polymerisation of C3H6 and showing 2 repeat units. Plus do we need to know how cracking occurs like long chain hydrocarbons and short chain hydrocarbon formation?

Polymerisation of Alkanes is not in the syllabus.

 

[BhaiArshad]

Can anyone tell me the products of oxidation of But-1-ene by Hot, Conc, Potassium Manganate(VII)?

Will it be Carboxylic Acid + CO2 + H2O?

 

[Farhad221]

in AS don't worry about it.

But what types of questions do you think will come up on the hybridization

 

[nehaoscar]

Can anyone tell me the products of oxidation of But-1-ene by Hot, Conc, Potassium Manganate(VII)?

Will it be Carboxylic Acid + CO2 + H2O?

Yes
CH3CH2COOH + CO2 + H2O

 

[Abdul Hanan]

But what types of questions do you think will come up on the hybridization

In AS i have seen no question of hybridization in past papers...

 

[Farhad221]

In AS i have seen no question of hybridization in past papers...

what a relief ok thanks . With maths and chem tomorrow i was freaking out if i had to remember hybridization .

 

[Mahnoorfatima]

Polymerisation of Alkanes is not in the syllabus.

i mean alkenes. Stupid autocorrect.

 

[BhaiArshad]

i mean alkenes. Stupid autocorrect.

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