P1 MCQ's preparation thread for chemistry ONLY!!!!

[mehranshaikh]

How can 3 different versions of X be formed? I can only count 2 different versions.

Summer 2010, Variant 12, Q25.

 

[Aries_95]

Will not the condition effect the product? i mean hot / cold oxidising agent?

nhin...i think not since i have not read it anywhere...I may be wrong.

 

[Aries_95]

ANY1 WITH ACCURATE N PRECISE PHYSICS CHEMISTRY NOTES??? POST THM.....DO REVISION GUIDDES WORK WELL????

I have notes for AS-Organic chemistry...here you go
Hope they are helpful
Yeah and do check out www.chemguide.co.uk
It is a very helpful website.

 

[angel456]

ye

nhin...i think not since i have not read it anywhere...I may be wrong.

yes it does affect the product formed...... when potassium manganate (VII) is added to an alkene if cold and dil. then the product formed is a diol and when hot conc. then the final product formed is a carbonyl compound

 

[Rahma Abdelrahman]

Nov 09 P12, can someone explain Q 18 , Q20 , Q22_Why not B? And Q40 ...
And in June 2010 P11 Q35?!!! How is it C?!! How is Carbon wrong while Sulfur is right?!!! I really don't get it!
Please reply asap ...

 

[Lyfroker]

q# 3, 9, 10, 23,28 & 32
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w04_qp_1.pdf

 

[itallion stallion]

Q.33
In a triple or a double bond, there is only ONE SIGMA BOND, the rest are PI bonds hence option 1 is wrong
the pi-bond cannot itself rotate hance the rotation can only take place along the sigma bond axis.
since option 2 and 3 are correct, the answer is C.

thanks alot!can u also explain q no 13.

 

[itallion stallion]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_11.pdf plz explain q9 with working.thanks!!

 

[mehranshaikh]

Nov 09 P12, can someone explain Q 18 , Q20 , Q22_Why not B? And Q40 ...
And in June 2010 P11 Q35?!!! How is it C?!! How is Carbon wrong while Sulfur is right?!!! I really don't get it!
Please reply asap ...

Q18: It says that when it was heated without any air so no compound was added or removed from the Ammonium Cynate. Only the addition of CNO will balance both sides Ammonium will be Nh4. The compound was NH4CNO
Q20: I have no idea about that.
Q22: Hydration and oxidation all occur at the double bond but after polymerisation the double bond will be gone so they can not occur. Hydrolysis with Chloro ethene is neucholophillic substitution so it occurs ar Chlorine not double bond and can happen in Polymer.
Q40: In Polymer atleast 2 molecules join together to form them. 1 mol of monomer producing 1 mol of polymer is impossible as monomer has to join, so it will reduce. Any other number is possible so the last 2 are correct. Answer C.

 

[Aries_95]

ye
yes it does affect the product formed...... when potassium manganate (VII) is added to an alkene if cold and dil. then the product formed is a diol and when hot conc. then the final product formed is a carbonyl compound

Yeah but we were talking about the effects of these conditions on products of oxidation of aldehydes

 

[Aries_95]

Nov 09 P12, can someone explain Q 18 , Q20 , Q22_Why not B? And Q40 ...
And in June 2010 P11 Q35?!!! How is it C?!! How is Carbon wrong while Sulfur is right?!!! I really don't get it!
Please reply asap ...

For Q.22:
Oxidation with cold KMNO4 produces diole is -OH will be attatched to both sides while in the polymer, only one side has OH attatched to it.
In C we first polymerise 1,2-dichloroethene which is then hydrolysed and the -Cl is replaced by -OH.
hence the answer is C.

 

[Dukeofwin]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_12.pdf Question 11 anyone?

 

[HongYue]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w08_qp_1.pdf

Can someone explain to me on question 7, 15 , 30, 32,39. Thx

 

[Aries_95]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w08_qp_1.pdf

Can someone explain to me on question 7, 15 , 30, 32,39. Thx

For Q.7:
Helium is monoatomic while hydrogen is diatomic hence Helium behaves more like an ideal gas. THe answer is therefore B.
Q.15:
Al atom in AlCl3 has an incomplete octet. you can check by drawing the ddot cross diagram of AlCl3. to complete the octet, the reaction takes place. hence the answer is C.
Q.32:
Bronsted Lowry acids are those which donate protons. all of the compds in the options can donate protons hence A is the answer.
Q.39:
Terminating step of free radical reaction involves the reaction between the free radicals to form a new product. Draw the products of the propogation reaction. the free radicals produced then react with each other. when you complete it, the answer is B.

 

[HongYue]

Thx a lot. Can you help me with one more question May/June 2008 question 6 ? http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s08_qp_1.pdf

 

[mehranshaikh]

Can someone explain Q22 to me please?
Summer 2011, Variant 12.

How does SOCl2 give the best yield? Why wouldn't NaCl?

 

[mehranshaikh]

How can 3 different versions of X be formed? I can only count 2 different versions.

Summer 2010, Variant 12, Q25.

 

[Obsidian Fl1ght]

MCQ:

A solid melts sharply just above 100°C. It doesn't conduct electricity even when molten.
It dissolves in hydrocarbon solvents.
What is the structure of the solid most likely to be?
A An atomic crystal
B An ionic crystal
C A giant molecular crystal
D A molecular crystal

I have eliminated B and D from the answers... but the remaining choices leave me getting mere shots in the dark and not sure answers.

 

[mehranshaikh]

MCQ:

A solid melts sharply just above 100°C. It doesn't conduct electricity even when molten.
It dissolves in hydrocarbon solvents.
What is the structure of the solid most likely to be?
A An atomic crystal
B An ionic crystal
C A giant molecular crystal
D A molecular crystal

I have eliminated B and D from the answers... but the remaining choices leave me getting mere shots in the dark and not sure answers.

B and C can be easily eliminated. The answer is D or A? And can you please tell me the year and number of this question?

 

[Xeshan16]

b

Q21- Substitute n by numbers 1 to 4. then find all isomers. There will be 7.
Q37- In 2 there will be only one ketone and one acid as there is one primary and one secondary C atom. In 3 a ketone and a dibasic acid will b produced. Only one has 2 secondary C atoms so it will produce 2 ketones.
Q39- H2SO4 will dehydrate the compounds. 1 on dehydration will produce an alkene which reacts with KMnO4. 2 also forms an alkene. 3 is an acid so it wont react with H2SO4.

Bro will acidic KMnO4 react with alkene?