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

[Xeshan16]

Q.26: You have to consider that there's an intermediate so there's two humps. The front hump is always higher than the second hump. I'm not sure why but it's just a basic rule, I think. XD
Q.27: Hydrolysis means substituting Br with OH group. So if all the Br are substituted, they would give you the same diol, wouldn't they? It's a nucleophilic substition reaction. And only the second organic compound can form H bond due to presence of OH group.
Q.33: CAtalyst does not increase KE of molecules. They lower the activation e so that molecules with lower KE can react. Catalyst also increases the rate of reaction whether it's backward or forward. It doesn't affect enthalpy change, same amount of energy released or used by reaction whether catalyst is there or not. It just speeds up the reaction.
Q.35: For the first: CaO + SO2 = CaSO3 thats correct
second: SO2+O2 = 2SO3 due to excess air then CaO + SO3 = CaSO4
third: CaO + CO = CaCO3 (lazy to balance) this is not a likely reaction as CO is neutral (but CO2 is acidic!) My lecturer helped with this question

Bro for question 35, SO2 need certain special conditions to covert to SO3 not only excess of air. So option 1 and 2 are both correct I mean B and D. Can you please explain?

 

[ahmed abdulla]

10. 2H2O <-> 2H2 + O2
I = 100(H2) 0(H2) 0(O2)
C = -2x(2H2O) +2x(2H2) +x(O2)
E = 80(2H2O)
x=1o, so the equilibrium concentration of H2=20, and of O2=10.
39. To dehydrate an alcohol, the C of the C-OH has to be attached to a C attached to an H. The C which it is attached to is attached to 4 Carbons and no Hydrogens.

cheers mate !

 

[KWIKIW]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s03_qp_1.pdf

Do you know how to do Qs 33 , 32, 20, 16, 11 in 01/M/J/2003(chemistry)?

 

[A*(a*)]

10. 2H2O <-> 2H2 + O2
I = 100(H2) 0(H2) 0(O2)
C = -2x(2H2O) +2x(2H2) +x(O2)
E = 80(2H2O)
x=1o, so the equilibrium concentration of H2=20, and of O2=10.
39. To dehydrate an alcohol, the C of the C-OH has to be attached to a C attached to an H. The C which it is attached to is attached to 4 Carbons and no Hydrogens.

 

[ahmed abdulla]

a>?

 

[ahmed abdulla]

2?

 

[h4rriet]

View attachment 28157

Is the answer D?

2?

Write the balanced equations for the combustion of 1 mole of all those compounds. For example, CH4+2O2->CO2+2H2O. 1 mole required 2 moles, so 10 moles (you can take the volume to be the number of moles) will require 20. 70-20=on the graph. Plus the volume of CO2.

 

[h4rriet]

View attachment 28157

Voltage is the energy needed to drive charge through. Energy gets used up as a current flows through a wire, so D is ruled out. A is ruled out because the voltage drop can't be smooth because the wire is of varying resistance. The gradient of the V/x graph = current, because x is proportional to R, and V/R=I. The gradient of the graph in B is decreasing and increasing in C, so the answer is B.

 

[h4rriet]

a>?

It has to be in Group I for its second ionisation energy to be higher.
Ca2+ : H+ = 1:2. Use n=cv to find the moles of H+, then use c=n/v and mole ratios to find the conc. of Ca2+.

 

[A*(a*)]

Voltage is the energy needed to drive charge through. Energy gets used up as a current flows through a wire, so D is ruled out. A is ruled out because the voltage drop can't be smooth because the wire is of varying resistance. The gradient of the V/x graph = current, because x is proportional to R, and V/R=I. The gradient of the graph in B is decreasing and increasing in C, so the answer is B.

how is the gradient of B decreasing? a dig. might help please Rest i got it.

 

[ahmed abdulla]

It has to be in Group I for its second ionisation energy to be higher.
Ca2+ : H+ = 1:2. Use n=cv to find the moles of H+, then use c=n/v and mole ratios to find the conc. of Ca2+.

you expain things in a short and understudable way ... thanks ... hats up !

 

[syed1995]

View attachment 28157

Is the answer B? cuz the gradient is decreasing... as amount of current will decrease.

 

[KWIKIW]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w07_qp_1.pdf

w07: 9 (b) , 10(d), could some one help ?

Answer for 10.
refer document.

 

[ahmed abdulla]

?
syed1995

 

[A*(a*)]

Is the answer B? cuz the gradient is decreasing... as amount of current will decrease.

Can you please explain me how?

 

[KWIKIW]

Do you know how to do Qs 33 , 32, 20, 16, 11 in 01/M/J/2003(chemistry)?
I am a little confused in these Qs.
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s03_qp_1.pdf

 

[h4rriet]

how is the gradient of B decreasing? a dig. might help please Rest i got it.

The steeper the line, the greater its gradient. If you look at B, the last line is steeper than the first. That means the NEGATIVE gradient is increasing, so overall it's decreasing. The first line of the graph of C is steeper than the last line, so the NEGATIVE gradient is decreasing, i.e. overall it's increasing.

 

[h4rriet]

Do you know how to do Qs 33 , 32, 20, 16, 11 in 01/M/J/2003(chemistry)?
I am a little confused in these Qs.
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s03_qp_1.pdf

11. An acid gives away H+ ions. It can give away more H+ ions if there's something that'll readily take H+ ions.
16. Write the equation for the reaction of Cl2 with NaOH.
20. Draw them all.
32. 1 is true because the S-O bond is polar. 2 is true. 3 is true too because there is no double-bonded C.

 

[KWIKIW]

11. An acid gives away H+ ions. It can give away more H+ ions if there's something that'll readily take H+ ions.
16. Write the equation for the reaction of Cl2 with NaOH.
20. Draw them all.
32. 1 is true because the S-O bond is polar. 2 is true. 3 is true too because there is no double-bonded C.

Thanks.
(16) Does Cl2 react with NaOH?
I don't know what the products are and I am confused on which equation to write.
(32)Why is statement 2 correct?
(20) Are the 2 trans isomers labelled 1 and 2 in my diagram same or different?
A rotation of atoms isn't possible about the double bond , so can the 2 trans isomers be different?
Or can there only be 1 cis isomer and only 1 trans isomer for a compound with a double bond?

 

[h4rriet]

Thanks.
(16) Does Cl2 react with NaOH?
I don't know what the products are and I am confused on which equation to write.
(32)Why is statement 2 correct?
(20) Are the 2 trans isomers labelled 1 and 2 in my diagram same or different?
A rotation of atoms isn't possible about the double bond , so can the 2 trans isomers be different?
Or can there only be 1 cis isomer and only 1 trans isomer for a compound with a double bond?

16. Yes it does, differently with cold dilute NaOH and hot concentrated NaOH. It's an equation we have to memorise. With cold dilute NaOH you get HClO and with hot concentrated NaOH you get HClO3. You also got NaCl and H2O in both.
32. Because the alkyl chain is hydrophobic, and oil too is hydrophobic.
20. The trans isomers you drew are the same! And there can be more than 1 cis and trans isomer depending on the groups attached. I'll draw all the cis and trans isomers and upload them in a sec. For the last one: change the positions of the Cl and H atoms to get different structural isomers.