Chemistry: Post your doubts here!

[Snowysangel]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_qp_12.pdf 25 D

Could someone explain this?

Please help!!!!
View attachment 45092[|quote]
Is it C?

 

[ZaqZainab]

But that makes a total of 7 carbons

isnt it he answer

 

[ZaqZainab]

C makes the most sense though. Because it can't be oxidized by kmno4 it has to be a tertiary alcohol with 3 different carbon groups attached to the central carbon

can you tell me the paper
cause i did a paper with the exact question some days back and the answer was 7

 

[ZaqZainab]

ok but 2 na in naoh reacts with cooh in other questionj

What?

 

[unique111]

Could someone explain this?

With conc. H2SO4, dehydration will occur. The OH of alcohol plus a H from neighbouring C is lost forming a double bond. Hope the picture helps.

 

[chishtyguy]

+1 to this.
anyone, help plz.
why not B?

U mean david Acaster. Roger Norris, Lawrie Ryan BOOK ?? Orange cover??!
I revise it,i am still scoring from 25 - 29
Thnx man
Inshallah i will

Yes that's the one, if that is your score then inshaAllah u will Obtain an A..

 

[Browny]

Please help!!!!

 

[ZaqZainab]

One hydrogen in place of carbon

then it becomes secondary and so it can be oxidized

 

[SIstudy]

Please help!!!!

Ans fr Q3 is C?

 

[Zepudee]

GUYSSSS. Gotta help me with this, PLEASEEE. hahahaha
Must be very easy for you guys!
Anyways, okay.
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_13.pdf
Q27 (C)

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_12.pdf
Q3 (B) Q8 (D) [ i guess all these answers correctly, but i dont understand why ]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_12.pdf
Q11 (A) [srsly no, what is this.]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
Q24 (B) , Q26 (A), Q30 (A)

THANK YOU SO SO MUCHHHHHH!! please help

 

[SIstudy]

GUYSSSS. Gotta help me with this, PLEASEEE. hahahaha
Must be very easy for you guys!
Anyways, okay.
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_13.pdf
Q27 (C)

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_12.pdf
Q3 (B) Q8 (D) [ i guess all these answers correctly, but i dont understand why ]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_12.pdf
Q11 (A) [srsly no, what is this.]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
Q24 (B) , Q26 (A), Q30 (A)

THANK YOU SO SO MUCHHHHHH!! please help

See for Q11
the equation should be kinda balanced
as in there is 1X in both reactant and product
while Y is only n in both sides
just take it as a normal eqation like Br2 -> 2Br- (n is the 2 here)
I hope yu get it

 

[2moora]

why is the answer D in Q7 s12 variant 2 ??

 

[Hijab]

Can someone plz plz plz answer this question...

 

[chishtyguy]

Which substance, in 1 mol dm–3 aqueous solution, would have the same hydrogen ion
concentration as 1 moldm
3 of hydrochloric acid?
A ethanoic acid
B nitric acid
C sodium hydroxide
D sulphuric acid

Answer is B. But the question is....WHY?

nitric acid HNO3 will dissociate into H+ +NO3-, just like HCL
Ethanoic hardly dissociates
NaOH is a base
When H2SO4 dissociates it gives 2 H+ ions.

 

[chishtyguy]

CH3CO2CH3 is behaving in the same way as the HCN was behaving with aldehyde
So when you work it out you'll know why the answer is C not B

Yr plz explain the structure... Aldehyde in C is Propanal and in B is ethanal... So why Its not B??

 

[Ahmed Aqdam]

hey i found u here too
can u help me with question 40 in this paper
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_qp_12.pdf

In statement 1, 2 moles of ethanoic acid will react with 1 mole of calcium ion as charge on calcium is +2. So compound will be Ca(CH3CO2)2 which has empirical formula CaC4H6O4.
In 2 and 3, both H from CO2H will be removed so empirical formula will be CaC4H4O4 and not CaC4H6O4.

 

[asfand798]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s08_qp_1.pdf

Guys please help me!
Q.8,10,18,21,27,28,29,30,32,33,34

 

[sudeep1097]

GUYSSSS. Gotta help me with this, PLEASEEE. hahahaha
Must be very easy for you guys!
Anyways, okay.
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_13.pdf
Q27 (C)

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w13_qp_12.pdf
Q3 (B) Q8 (D) [ i guess all these answers correctly, but i dont understand why ]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_12.pdf
Q11 (A) [srsly no, what is this.]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
Q24 (B) , Q26 (A), Q30 (A)

THANK YOU SO SO MUCHHHHHH!! please help

3 is B just use stoichiometric ratios 1 mole IO3 reacts with 2 mole cl while 1 mole I2 reacts with 4 mole cl which is like 1 mole I2 reacting with 2 mole Io3 that is 1:2 ratio
I would like help with 8 D too

 

[SIstudy]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_11.pdf
Q23 ?? :/ (ANS - B)
I don't really get the compound C drawn :S

 

[papajohn]

Q28 C how??
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s13_qp_13.pdf