Chemistry: Post your doubts here!

[The Sarcastic Retard]

View attachment 57487
pls help

R and n is constant.
P1V = T1
1*10^5 * V = 293
V = 2.93*10^-3
Total V = 4(V)
P2 * 4(V) = T2
V = A

 

[The Sarcastic Retard]

http://studyguide.pk/Past Papers/CIE/International A And AS Level/9701 - Chemistry/9701_w06_qp_1.pdf

q:37 please
Answer is D

1) It has 2 ketone groups present in both product.
2) On double bond means only 1 product so 2 is wrong.
3) One product has both ketone (di-ketone), so 3 is wrong.

 

[The Sarcastic Retard]

27 Which compound • is unaffected by hot alkaline potassium manganate(VII); • gives hydrogen when treated with sodium?

A (CH3)2CHCOCH3
B (CH3)3COH
C CH3CH2CH(OH)CH3
D CH3CO2CH(CH3)2

right answer is B ... but why not C? how is C affected bby KMnO4?

B is tertiary alcohol. It cant be oxidised.
C is secondary, so it will be oxidised to ketone.
Both B and C will react with Na metal as OH group is present in both.

 

[The Sarcastic Retard]

View attachment 57488


why not SO4 2- is high?

From eqn 1 : We can get an idea that HSO4- will have lower concentration. And when SO4(2-) is formed from that, how u can say that it will be high?

 

[The Sarcastic Retard]

View attachment 57490

how to go about questions like these?

You can use trial and error method or go like this :~

 

[awesomaholic101]

Which question are u talking about?

Generally, i mean. They ask questions like why S02 is used as food preservative ... or why MgO is used for lining refractory kilns or sth ... so do you have like a list of things and it's uses that we can go through?

OH is a nucleophile, it will attack on aldehyde. You can compare reaction with HCN

the OH group in the ethanol ... i see. Thank you.

 

[The Sarcastic Retard]

Generally, i mean. They ask questions like why S02 is used as food preservative ... or why MgO is used for lining refractory kilns or sth ... so do you have like a list of things and it's uses that we can go through?


the OH group in the ethanol ... i see. Thank you.

No that was what my teacher made me learn in inorganic chemistry.
some things are asked from IGCSE level....

 

[awesomaholic101]

No that was what my teacher made me learn in inorganic chemistry.
some things are asked from IGCSE level....

ok ok

 

[The Sarcastic Retard]

ok ok

So prepared?

 

[ahmed butt]

Q30 ? i am getting 8 ketone functional group how to solve?
http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w14_qp_11.pdf
http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w14_ms_11.pdf

 

[donewithtime80]

1) It has 2 ketone groups present in both product.
2) On double bond means only 1 product so 2 is wrong.
3) One product has both ketone (di-ketone), so 3 is wrong.

how can 1 double bond mean only one product? doesn't each double bond breaking result in two products?

 

[The Sarcastic Retard]

how can 1 double bond mean only one product? doesn't each double bond breaking result in two products?

The product will be a straight chain

 

[The Sarcastic Retard]

Q30 ? i am getting 8 ketone functional group how to solve?
http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w14_qp_11.pdf
http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w14_ms_11.pdf

How 8?

 

[The Sarcastic Retard]

Anyone?

 

[ahmed butt]

Anyone?

Just memorise its always CNO- its always repeating

 

[The Sarcastic Retard]

Just memorise its always CNO- its always repeating

I want a proper reasoning. Thanks though

 

[ahmed butt]

I want a proper reasoning. Thanks though

which year is it? so i can explain better

 

[chocolatelover]

Is the answer A?
5/15*12 + 10/15*6 = 8 kPa

Yes it is. Thank you!

 

[The Sarcastic Retard]

which year is it? so i can explain better

I dont remember.

 

[nehaoscar]

I have relooked at the question and spotted my mistake.

The concentration of Fe2(SO4)3 is o.1 mol/dm3. But since we are using concentration of Fe3+ , we do need to multiply it by 2 as there are two Fe3+ ions for each Fe2(SO4)3.

Could you please show the equations as I'm slightly confused how you know there are two Fe3+ ions for each Fe2(SO4)3