Chemistry and Physics AS paper 12 MCQS

[cute97]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s07_qp_1.pdf
Q2 and Q25 pls
thanks in advance

 

[syed1995]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s07_qp_1.pdf
Q2 and Q25 pls
thanks in advance

Q2 B. Number of Moles = 120/24000 = 5x10^-3 moles

Mr = mass/moles
Mr = 0.23/5x10^-3
Mr = 46..

Now test each one out..

14x+16y should be 46.. It happens in B.
14*1+16*2=46

Q25. C.

That's simple..

Haloalkanes undergoes nucleophilic substitution with KCN to form -CN .. and then adding HCl to the -CN compound converts -CN to COOH... so answer is

 

[Malik777]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w09_qp_12.pdf
Q 27 plz

 

[cute97]

Q2 B. Number of Moles = 120/24000 = 5x10^-3 moles

Mr = mass/moles
Mr = 0.23/5x10^-3
Mr = 46..

Now test each one out..

14x+16y should be 46.. It happens in B.
14*1+16*2=46

Q25. C.

That's simple..

Haloalkanes undergoes nucleophilic substitution with KCN to form -CN .. and then adding HCl to the -CN compound converts -CN to COOH... so answer is

thank you but i wonder for Q25 always adding HCl to a Cynaide will give COOH grp ??? thnxx for your tym

 

[cute97]

View attachment 28330
syed1995 please help! Thanks

what is the answer for this and how pls ??

 

[syed1995]

thank you but i wonder for Q25 always adding HCl to a Cynaide will give COOH grp ??? thnxx for your tym

Yes.

 

[adithya909]

Can someone help me out with these questions in physics please ? it would be of great help ; Paper mj 2010 variant 11

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_11.pdf

questions :- 27, 29 , 33 , 38 , 40 .

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_13.pdf

questions :- 14 , 31 , 37 .

Thanking you in advance !

 

[snowbrood]

Can someone help me out with these questions in physics please ? it would be of great help ; Paper mj 2010 variant 11

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_11.pdf

questions :- 27, 29 , 33 , 38 , 40 .

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_13.pdf

questions :- 14 , 31 , 37 .

Thanking you in advance !

for Q27 the charge does move in direction of force applied by the charge as the centre of the circle the force applied is toward that charge inwards since the charge does not move in direction of force applied so that is zero.
for Q29 electron will always move in direction parallel to the direction of the beam. electron repel electron so it would move in opposite direction
for Q33 find total resistance
u will get 1.5R we know
P so P=I^2R

I=V/R. P=(V^2/R^2)*R here u will get

P=V^2/R.

V^2 =12*1.5R

square root both sides
V=(18R)^0.5
V1=(R1/R1+R2)*Emf of cell.
P=[{(0.5/1.5)*(18R)^0.5}^0.5]/R.
solve this u will get P=2

 

[adithya909]

for Q27 the charge does move in direction of force applied by the charge as the centre of the circle the force applied is toward that charge inwards since the charge does not move in direction of force applied so that is zero.
for Q29 electron will always move in direction parallel to the direction of the beam. electron repel electron so it would move in opposite direction
for Q33 find total resistance
u will get 1.5R we know
P so P=I^2R

I=V/R. P=(V^2/R^2)*R here u will get

P=V^2/R.

V^2 =12*1.5R

square root both sides
V=(18R)^0.5
V1=(R1/R1+R2)*Emf of cell.
P=[{(0.5/1.5)*(18R)^0.5}^0.5]/R.
solve this u will get P=2

thanks if u can help me solve the others too it would be a greater help

 

[Ahmedraza73]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_11.pdf
help me someone with the question no:11,27,29

 

[mariamh]

October November 2002
Q3 and 9
Chemistry

 

[snowbrood]

thanks if u can help me solve the others too it would be a greater help

yea sure buddy there u go well i had a appointment for a dentist so couldnt solve the remaining question sorry for making u wait
for question 38
after beta decay element's proton increases by one
here it becomes 4 mass number remains unchanged
mass number 8
proton number 4
number of neutrons 8-4=4
only A has 4 neutrons and 4 protons so this is correct

for question 40
2 alpha decays followed by beta decay.
217-(2*4)=209
85-(2*2)+1( 2 alpha decays so 2+2=2*2 and proton number increases by 1 in beta decay=82
so C is correct

 

[snowbrood]

thanks if u can help me solve the others too it would be a greater help

Can someone help me out with these questions in physics please ? it would be of great help ; Paper mj 2010 variant 11

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_11.pdf

questions :- 27, 29 , 33 , 38 , 40 .

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_13.pdf

questions :- 14 , 31 , 37 .

Thanking you in advance !

for Q14
for the moment of forces, you'll have to consider the perpendicular distance form the point of application of force and the axis. in your case, 10N and 5N act counter-clockwise and the 15N acts clockwise. consider clockwise direction to be positive and then find the moments of forces acting and add them up to get the resultant.
-5(2)-10(2)+15(3)=15

for Q31
first find the total resistance
(16/0.6)+(0.05*800*2) ( i multiplied it with two as there are two wire so )
34.67 total resistance
V=IR=0.6*34.67=20.8

 

[snowbrood]

thanks if u can help me solve the others too it would be a greater help

for last question look the easiest method here is to visualize see (u are a charge) if u have only one route then the resistors are in series and if u go two or more routes then it is parallel.
three 10 ohm resistors in series so add them this makes 1 30 ohm resistor which is parallel to 10 ohm u get 7.5 which is between 1 and 10 ohm

 

[adithya909]

for last question look the easiest method here is to visualize see (u are a charge) if u have only one route then the resistors are in series and if u go two or more routes then it is parallel.
three 10 ohm resistors in series so add them this makes 1 30 ohm resistor which is parallel to 10 ohm u get 7.5 which is between 1 and 10 ohm

thanks a lot buddy how is ur teeth now ?

 

[snowbrood]

thanks a lot buddy how is ur teeth now ?

perfect thanks for asking May God Shower his blessing upon u

 

[snowbrood]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_11.pdf
help me someone with the question no:11,27,29

for question at lower temperature maxima shifts to left and at a greater value of Y (Y axis) only A is correct if u consider this
i believe 27 is not a valid question hydrogen rich carbon in double bond will become more hydrogen rich here .
it should be homolytic and 1:3 as 2-chloropropane will be major product
for Q 29
there is no cis trans isomer for a carbon atom of double bond having two same groups attached . to the left carbon has two methyl attached to it
there is only one pair of cis trans isomers possible i.e for double bond in right.

 

[snowbrood]

October November 2002
Q3 and 9
Chemistry

for Q3 to form ion2+ u need energy that is the sum of first and second ionisation
when u refer to databooklet u will realize aluminium needs 1820+577=2397
and cobalt also needs 757+1640=2397 see energies are same
for Q9 i will solve it i am tired at the moment

 

[Aries_95]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s07_qp_1.pdf
Q2 and Q25 pls
thanks in advance

Q.25: C.
Nucleophilic substitution takes place when KCN in ethanol reacts with 1-bromopropane. Br is replaced by CN. Acid hydrolysis of Nitril cause it to convert to carboxxylic acid hence producing butanoic acid.

 

[lubna1232]

for Q3 to form ion2+ u need energy that is the sum of first and second ionisation
when u refer to databooklet u will realize aluminium needs 1820+577=2397
and cobalt also needs 757+1640=2397 see energies are same
for Q9 i will solve it i am tired at the moment

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w09_qp_12.pdf

q4,8,9,12,13,18,20,21,25

this paper was a tough one please help me with these?