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

[Lyfroker]

Q#15, 18, 22, 27, 37 & 40
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w03_qp_1.pdf

 

[Lyfroker]

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

 

[queen of the legend]

1 In which species does the underlined atom have an incomplete outer shell?

ABF3 CH3

– C F2O D H3O

M/J 2012 - 11

why is it A ,,,,I marked CH3 ?!

question 1 and 2 plsssss

 

[1597.2217]

Q#15, 18, 22, 27, 37 & 40
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w03_qp_1.pdf

Q15:

Over here you need to write the equations of the decomposition of each compound.
MgCl2 ---> Mg + Cl2
MgCO3 → MgO + CO2
2 Mg(NO3)2 → 2 MgO + 4 NO2 + O2
Mg(OH)2 → MgO + H2O

It cannot be (C) because 2.5 mole of gases are formed. Could be either A, B or C. That's all I can say. Sorry.

Q18:

Hydrogen bonds are formed with F,O,N. Hydrogen bonds are formed so it is either (C) or (D). Ammonia dissolved to give ions, so the answer is (D).

Q22:

With the provided data, form an equation.

X ---> 5 C2H2 + C3H8 + C4H8 [Calculate the C and H.]

Answer is hence C17H36 (B).

Q27:

(A) will oxidize both primary alcohols to Aldehyde
(C) will give haloganoalkane with both
(D) will replace H in the OH.

Answer must be hence be (B). It will form Alkene with latter alcohol.

Q37:

Photochemical chlorination means free-radical substitution.

CH4 + Cl ---> CH3Cl + H
H + Cl ---> HCl
CH3Cl + Cl ---> CH2Cl2 + H [This H free radical will react with Chlorine free radical to form HCl.]

Answer must be C because in excess of Chlorine, the H free radicals will react with Cl.

Q40:

I can't do this.

 

[Eshika]

In a car engine pollutant oxide Y, which contains non-metallic element X, is formed.
Further oxidation of Y to Z occurs in the atmosphere. In this further oxidation, 1 mol of Y reacts
with 0.5mol of gaseous oxygen.
X could be either nitrogen or sulfur.
Which statements about X, Y and Z can be correct?
1 The oxidation number of X increases by two from Y to Z.
2 Y may have an unpaired electron in its molecule.
3 Y is a polar molecule.
How do u find the ans???

 

[1597.2217]

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

Q3-

1 mole CH3SH reacts with 3 mole O2. So 10 cm^3 of CH3SH reacted with 30cm^3 of O2. (30 cm^3 was excess). It formed CO2 and SO2 gasses, which are also 10cm^3. The answer must be 30+10+10= 50cm^3 which is (C).

Q9-

(A) is alcohol
(B) is alkane
(C) is acid
(D) is ketone.

Only A and B would combust. A is liquid and B is a gas. B should react explosively.

Q10-

This is very simple. Atm is 1.0 and 1 Atm is 1.1, only D has total pressure of 1.1 so obviously D.

Q23-

List out the products. Isomers of C2H4Br2, isomers of C2H5Br, H2 and HBr.
5 Isomers of C2H4Br2, 2 isomers of C2H5Br are possible so answer is 5+2+2 = 9. (D)

Q28-

A will give 1
B will give 2
C will give 1
D will give 1

So answer is (B).

Q32-

This is very simple! The answer is (C) because a low temperature of 450 is used since the reaction is exothermic. The yield is about 14% and Pressure is between 100-300.

 

[istudent]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_12.pdf
plz help in Q7 and Q34

 

[1597.2217]

1 In which species does the underlined atom have an incomplete outer shell?

ABF3 CH3

– C F2O D H3O

M/J 2012 - 11

why is it A ,,,,I marked CH3 ?!

question 1 and 2 plsssss

Q1-

It is not CH3- because of the overall negative charge shown. Boron is in group 3 and it has 3 electrons in its outer shell. Bonding with Flourine means it loses 3 electrons.

Q2-

A- Decreasing the size of catalyst means slower forward reaction.
B- Increasing the pressure means faster forward reaction.
C- Increasing the temperature would favor backward reaction.
D- Removing ammonia as it is formed would change the rate of ammonia being formed, just the yield. So answer is D.

 

[1597.2217]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_12.pdf
plz help in Q7 and Q34

Please search the thread, question 7 has been answered multiple times. As for 34, i don't know how to find the answer.

 

[Lyfroker]

Q3-

1 mole CH3SH reacts with 3 mole O2. So 10 cm^3 of CH3SH reacted with 30cm^3 of O2. (30 cm^3 was excess). It formed CO2 and SO2 gasses, which are also 10cm^3. The answer must be 30+10+10= 50cm^3 which is (C).

Q9-
(A) is alcohol
(B) is alkane
(C) is acid
(D) is ketone.

Only A and B would combust. A is liquid and B is a gas. B should react explosively.

Q10-

This is very simple. Atm is 1.0 and 1 Atm is 1.1, only D has total pressure of 1.1 so obviously D.

Q23-

List out the products. Isomers of C2H4Br2, isomers of C2H5Br, H2 and HBr.
5 Isomers of C2H4Br2, 2 isomers of C2H5Br are possible so answer is 5+2+2 = 9. (D)

Q28-

A will give 1
B will give 2
C will give 1
D will give 1

So answer is (B).

Q32-

This is very simple! The answer is (C) because a low temperature of 450 is used since the reaction is exothermic. The yield is about 14% and Pressure is between 100-300.

Thnx

 

[istudent]

In a car engine pollutant oxide Y, which contains non-metallic element X, is formed.
Further oxidation of Y to Z occurs in the atmosphere. In this further oxidation, 1 mol of Y reacts
with 0.5mol of gaseous oxygen.
X could be either nitrogen or sulfur.
Which statements about X, Y and Z can be correct?
1 The oxidation number of X increases by two from Y to Z.
2 Y may have an unpaired electron in its molecule.
3 Y is a polar molecule.
How do u find the ans???




As he has stated non metal is X so when it react with .5 mole of oxygen to balance its -2 oxidation its oxidation no will increase by 2.secondly it say it may have unpaired electron in form of Y so does have N in NO. Thirdly if Y is SO2 then it is polar because of difference in bond polarity in it they are not cancelled because molecule is bent

 

[1597.2217]

In a car engine pollutant oxide Y, which contains non-metallic element X, is formed.
Further oxidation of Y to Z occurs in the atmosphere. In this further oxidation, 1 mol of Y reacts
with 0.5mol of gaseous oxygen.
X could be either nitrogen or sulfur.
Which statements about X, Y and Z can be correct?
1 The oxidation number of X increases by two from Y to Z.
2 Y may have an unpaired electron in its molecule.
3 Y is a polar molecule.
How do u find the ans???

1 is true. 2 is true. Not sure about 3.
1 is true because oxidation is gain in oxygen, which increases your oxidation number.
2 is true because Y cannot be changed to Z without unpaired electrons.

 

[Mairaxo]

b

Bro will acidic KMnO4 react with alkene?

yeah sorry it does react and an O is attached to both ends of the double bond! my bad

 

[Eshika]

An organic compound, X, will react with an excess of calcium metal to produce a salt with the
empirical formula CaC4H6O4.

What could be the identity of X?
1 ethanoic acid
2 butanedioic acid
3 methylpropanedioic acid
what is the ans? and how do we solve dis?

 

[Razo513]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_12.pdf
plz help in Q7 and Q34

Q7 was answered previously as for Q34
AgCl + 2NH3 --> Ag[(NH3)2] + Cl-
1) Nitrogen in NH3 has five electrons in its outer shell. Three of these form normal covalent bonds with one electron from each of the hydrogen atoms. That leaves two non-bonded electrons ..a lone pair .. on the nitrogen atom. These are donated to the Ag ion forming a dative covalent or coordinate bond.
thus 1 is correct

2) assign oxidation numbers, ull see that N has the oxidation number -3 before and after the reaction

3) ammonia didnt accept any protons for it to be considered a bronsted lowry base

thus the answer is B (1 &2)

 

[Rabb94]

on 10 paper 12
8,13,14

 

[Mairaxo]

ans is 2?

An organic compound, X, will react with an excess of calcium metal to produce a salt with the
empirical formula CaC4H6O4.

What could be the identity of X?
1 ethanoic acid
2 butanedioic acid
3 methylpropanedioic acid
what is the ans? and how do we solve dis?

 

[1597.2217]

on 10 paper 12
8,13,14

Q8-
-1565 is the energy required to get Ca2+ (aq) ions.
+177 is the energy required to change Ca solid to gas.

In the original equation we see that Ca solid is changed to Ca2+ (aq).
For this,

-1565 +177 + 590 + 1150 = +352 [590 is the first ionization energy and 1150 is the second ionization energy.]
Answer is (D).

Q13-
This is simple balancing.
m=5
n=2
p=1
q=5

(B)

Q14-

First we find the moles of Calcium Nitrate.
Ca(NO3)2 Mr= 161.4g
Moles of salt= 4.1/161.4 = 0.0254 moles

Thermal decomposition of Ca(NO3)2 gives CaO + 2 NO + o.5 O2 [YOU MUST LEARN THIS EQUATION. I'VE SEEN THIS IN MANY PAPERS. FREQUENTLY REPEATED.]

NO and O2 are gases, they will fly off leaving solid CaO. We need to find it's mass which is moles x Mr.
0.0254 x 56.1 = 1.4249g

Answer is (C) 1.40 g.

 

[Rabb94]

Q8-
-1565 is the energy required to get Ca2+ (aq) ions.
+177 is the energy required to change Ca solid to gas.

In the original equation we see that Ca solid is changed to Ca2+ (aq).
For this,

-1565 +177 + 590 + 1150 = +352 [590 is the first ionization energy and 1150 is the second ionization energy.]
Answer is (D).

Q13-
This is simple balancing.
m=5
n=2
p=1
q=5

(B)

Q14-

First we find the moles of Calcium Nitrate.
Ca(NO3)2 Mr= 161.4g
Moles of salt= 4.1/161.4 = 0.0254 moles

Thermal decomposition of Ca(NO3)2 gives CaO + 2 NO + o.5 O2 [YOU MUST LEARN THIS EQUATION. I'VE SEEN THIS IN MANY PAPERS. FREQUENTLY REPEATED.]

NO and O2 are gases, they will fly off leaving solid CaO. We need to find it's mass which is moles x Mr.
0.0254 x 56.1 = 1.4249g

Answer is (C) 1.40 g.

thanks

 

[Lyfroker]

Q#2, 29, 30 & 38
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s03_qp_1.pdf