Chemistry: Post your doubts here!

[Rizwan Javed]

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that was awesome!
thank you so much

No problem

 

[funky brat]

In the infrared spectroscopy question given at the end of the book (the Roger Norris thing) there's a question which asks to state the three distinct points for indentifying the compound or more generally if theres such a question in which there is only one identifiable peak for say OH group and then other complicated peaks occur in the fingerprint region, what could be the three reasons to state?

 

[Rizwan Javed]

In the infrared spectroscopy question given at the end of the book (the Roger Norris thing) there's a question which asks to state the three distinct points for indentifying the compound or more generally if theres such a question in which there is only one identifiable peak for say OH group and then other complicated peaks occur in the fingerprint region, what could be the three reasons to state?

Can you please post the picture of that question?

 

[ahmedish]

Should I study infrared spectroscopy if im doing A2? can it come in Paper 4 ? (its a new addition to the AS syllabus)

 

[The Sarcastic Retard]

Should I study infrared spectroscopy if im doing A2? can it come in Paper 4 ? (its a new addition to the AS syllabus)

It myt come.

 

[ahmedish]

It myt come.

Man but wtf where do they expect us to learn it.
Its quite big as well.
Did you study it?

 

[princess Anu]

http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_s08_ms_5.pdf

Q1c
Temp rise is included in independent as well as dependent variable :/
WHY

 

[Eugene99]

D. how?

 

[Dark Destination]

View attachment 60524

D. how?

I think because the products of A and C are both carboxylic acids, which have hydrogen bonding between their molecules.
There won't be any reaction for B, cause it's a tertiary alcohol.

The product of D is a ketone, which doesn't have hydrogen bonding between its molecules, leading to a lower boiling point?

I'm sorry if I'm wrong. This is probably the first chemistry question I tried in like months...

 

[Eugene99]

I think because the products of A and C are both carboxylic acids, which have hydrogen bonding between their molecules.
There won't be any reaction for B, cause it's a tertiary alcohol.

The product of D is a ketone, which doesn't have hydrogen bonding between its molecules, leading to a lower boiling point?

I'm sorry if I'm wrong. This is probably the first chemistry question I tried in like months...

you are right about A and C, but actually ketones have higher boiling points, because they have two alkyl groups on either side of their C=O which makes it more stable. which is why I was confused
Hasn't it got something to do with branching?
But branched also have lower boiling points

 

[Rizwan Javed]

I think because the products of A and C are both carboxylic acids, which have hydrogen bonding between their molecules.
There won't be any reaction for B, cause it's a tertiary alcohol.

The product of D is a ketone, which doesn't have hydrogen bonding between its molecules, leading to a lower boiling point?

I'm sorry if I'm wrong. This is probably the first chemistry question I tried in like months...

You are right :3

 

[The Sarcastic Retard]

I think because the products of A and C are both carboxylic acids, which have hydrogen bonding between their molecules.
There won't be any reaction for B, cause it's a tertiary alcohol.

The product of D is a ketone, which doesn't have hydrogen bonding between its molecules, leading to a lower boiling point?

I'm sorry if I'm wrong. This is probably the first chemistry question I tried in like months...

Its correct.

 

[Dark Destination]

you are right about A and C, but actually ketones have higher boiling points, because they have two alkyl groups on either side of their C=O which makes it more stable. which is why I was confused
Hasn't it got something to do with branching?
But branched also have lower boiling points

Yeah, but still no hydrogen bonding which is a strong force of attraction leading to increased boiling points. Absence of it would surely lower the boiling point.

And yes, I think straight chain alkanes have HIGHER boiling points cause of more contact point or something... but the comparison here is clearly because of the intermolecular forces of attraction.

 

[Eugene99]

Yeah, but still no hydrogen bonding which is a strong force of attraction leading to increased boiling points. Absence of it would surely lower the boiling point.

And yes, I think straight chain alkanes have HIGHER boiling points cause of more contact point or something... but the comparison here is clearly because of the intermolecular forces of attraction.

get that..thank you

 

[Dark Destination]

You are right :3

Yayyy. Chemistry is easy.

 

[funky brat]

Yayyy. Chemistry is easy.

Chemistry MCQs game strong.

 

[Dark Destination]

Chemistry MCQs game strong.

Nah. Just one MCQ.

 

[Dark Destination]

So does anyone have any other tough MCQ's? I really feel like trying a TRICKY MCQ. Want a challenge. :/

 

[Rizwan Javed]

So does anyone have any other tough MCQ's? I really feel like trying a TRICKY MCQ. Want a challenge. :/

Should I give?

 

[Dark Destination]

Should I give?

Yes, please. Give the toughest MCQ you have! I really want something TOUGH.