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

snowbrood

snowbrood

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A n g e l a ♥ said:
Thanx ALOT !!


Q 9 & 4 OF oct\nov 2011 V1
Click to expand...
mind if i help u here
for Q4
nitrogen will have a lone pair as it should complete its octet right.
we consider double bond and single bond to have same effect on the bond angle .
we treat that(double bond) as one ok

so here are 3 three pairs right 3 means trigonal planor .. because of lone pair it would have bond angle less than 120 but here we are to approximate so 120 is the bond angle
 
snowbrood

snowbrood

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A n g e l a ♥ said:
Thanx ALOT !!


Q 9 & 4 OF oct\nov 2011 V1
Click to expand...
for Q9 for solids there is no Kc or Kp so it wont be considered.
initially there were 1 mole of Ag ion
there were 0.44 moles of Ag ion left in equilibrium so 0.56 moles of Ag ion reacted to for 0.56 of Fe3+
we had initial 1 mole of Fe2+ as 1 mole of FeSO4 is available so we will have 0.44 moles of Fe2+ left
0.56/0.44*0.44 we get 2.89
 
Mairaxo

Mairaxo

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sweetjinnah said:
i need help in these mcq's 21,37 nd 39...
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w06_qp_1.pdf
Click to expand...
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.
 
sweetjinnah

sweetjinnah

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Mairaxo said:
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.
Click to expand...

thankss alot:)
 
h4rriet

h4rriet

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itallion stallion said:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_11.pdf how to do q2(why option c is wrong),9,27,36(why is 3 corrct).thanks alot!
Click to expand...

3. The RATE of the reaction is what's being talked of. The RATE will increase with a rise in temperature.
9. Write down the initial moles, then the change in moles, then the equilibrium moles, then add the equilibrium moles.
27. The C-I bond breaks fastest because it's the weakest.
36. 1 is true. 2 is true because high pressures favour the side of the fewer molecules. The rate of the backward reaction increases because the concentration of the products increases.
 
itallion stallion

itallion stallion

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h4rriet said:
3. The RATE of the reaction is what's being talked of. The RATE will increase with a rise in temperature.
9. Write down the initial moles, then the change in moles, then the equilibrium moles, then add the equilibrium moles.
27. The C-I bond breaks fastest because it's the weakest.
36. 1 is true. 2 is true because high pressures favour the side of the fewer molecules. The rate of the backward reaction increases because the concentration of the products increases.
Click to expand...

in question no 9,at equilibrium moles of p will be (2-x),R will be (x).adding them togather & putting them equal to (2+x).still confused!!

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_12.pdf .kindly also tell these qusetions.2(why not B),10,33.thanks alot!!!
 
ahmed abdulla

ahmed abdulla

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Which pair of reagents will take part in a redox reaction?
A CH3CH2OH + concentrated H2SO4
B CH3CHO + Tollens’ reagent
C CH3CO2C2H5 + dilute H2SO4
D CH3COCH3 + Fehling’s solution
 
Malik777

Malik777

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Plz Answer with method :/ (Hess law)
 

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leosco1995

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Lyfroker said:
q# 5, 15, 16, 17, 20 & 24
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w05_qp_1.pdf
please explain
Click to expand...

HCl since it has strong attractions (H+ and Cl-) .. so it deviates more from ideal gas behaviour (there should be minimal attraction between the atoms for ideal behaviour).

He has no ionic charge with very weak interactions.
CH4 is wrong because it is non-polar with weak interactions.
N2 also has weak interactions.

Q15) Ca(NO3)2 -> CaO + 2NO2 + O2

mass of calcium nitrate : volume of oxygen (1 mole = 24 dm^3)

164g24 dm^3
8.2gx dm^3

1.2 dm^3 = 1200 cm^3.
 
Malik777

Malik777

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Malik777 said:
Plz Answer with method :/ (Hess law)
Click to expand...

leosco1995 said:
HCl since it has strong attractions (H+ and Cl-) .. so it deviates more from ideal gas behaviour (there should be minimal attraction between the atoms for ideal behaviour).

He has no ionic charge with very weak interactions.
CH4 is wrong because it is non-polar with weak interactions.
N2 also has weak interactions.

Q15) Ca(NO3)2 -> CaO + 2NO2 + O2

mass of calcium nitrate : volume of oxygen (1 mole = 24 dm^3)

164g24 dm^3
8.2gx dm^3

1.2 dm^3 = 1200 cm^3.
Click to expand...

answer mine :/
 
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