anyone there help me with chem mcq ?

[Z.S.M]

what about q 25 in the same ppr ?how will i khow ?

Omit A, because that's cracking and requires high temperature and catalyst.
Omit B, because halogenoalkanes require heating to initiate reaction.
Check reaction conditions for reation C (you must know them by now).
You're left with D, which is the answer.

P.S For questions like these, revise ALL the reaction conditions mentioned in the syllabus.

 

[Pwincessajwa]

Omit A, because that's cracking and requires high temperature and catalyst.
Omit B, because halogenoalkanes require heating to initiate reaction.
Check reaction conditions for reation C (you must know them by now).
You're left with D, which is the answer.

P.S For questions like these, revise ALL the reaction conditions mentioned in the syllabus.

ahan thankssssssssssssssssssssssssssssssssssssssssssssss alottttttttttt

 

[Z.S.M]

ahan thankssssssssssssssssssssssssssssssssssssssssssssss alottttttttttt

No problem.

 

[Pwincessajwa]

Omit A, because that's cracking and requires high temperature and catalyst.
Omit B, because halogenoalkanes require heating to initiate reaction.
Check reaction conditions for reation C (you must know them by now).
You're left with D, which is the answer.

P.S For questions like these, revise ALL the reaction conditions mentioned in the syllabus.

what about question 32 ?

 

[Z.S.M]

what about question 32 ?

Q32. B
Carbon is oxidized from 0 to 2+, so is a reducing agent.
Mg is oxidized from 0 to 2+, so is a reducing agent too.
Statements 1 and 2 are correct.
Chlorine is reduced from 0 to 1-, so is an oxidizing agent.
Statement 3 is therefore incorrect.

 

[Pwincessajwa]

Q32. B
Carbon is oxidized from 0 to 2+, so is a reducing agent.
Mg is oxidized from 0 to 2+, so is a reducing agent too.
Statements 1 and 2 are correct.
Chlorine is reduced from 0 to 1-, so is an oxidizing agent.
Statement 3 is therefore incorrect.

question 39,40 ? sorry if i am disturbing but i have exam tommorow so i have million doubts

 

[Z.S.M]

question 39,40 ? sorry if i am disturbing but i have exam tommorow so i have million doubts

No problem. I understand. Just don't overwork yourself.
Answers coming right up.

 

[Z.S.M]

Q40. You need to recall the reaction conditions again. Only the third reaction is exothermic as shown by the graph. The first two require an input of energy (heat), so we can rule them out. Answer is therefore D.

 

[Pwincessajwa]

Q40. You need to recall the reaction conditions again. Only the third reaction is exothermic as shown by the graph. The first two require an input of energy (heat), so we can rule them out. Answer is therefore D.

thank u so much

 

[Z.S.M]

Q39. Convert all the reactants and products into moles. And find the percentage yield by products/reactants x 100.

Statement 1:
Moles of reactants = 74.00/ (4x12 + 1x10 + 16) = 1 mole
Moles of products = 44.64 / (4x12 + 16 + 1x8) = 0.62 moles
Yield = (0.62/1) x 100 = 62%
Correct

Statement 2:
Moles of reactants = 74.00/ (4x12 + 1x10 + 16) = 1 mole
Moles of products = 54.56 / (4x12 + 2x16 + 1x8) = 0.62 moles
Yield = (0.62/1) x 100 = 62%
Correct

Statement 3:
Moles of reactants = 74.00/ (4x12 + 1x10 + 16) = 1 mole
Moles of products = 54.56 / (4x12 + 2x16 + 1x8) = 0.62 moles
Yield = (0.62/1) x 100 = 62%
Correct

Answer is A.

 

[Z.S.M]

thank u so much

My pleasure.

 

[Pwincessajwa]

My pleasure.

can u also help me with oct/nov 2009 q14,20,27,28,30,40 plz ?

 

[handsomeROB]

thank u so much

ur welcome..

 

[Z.S.M]

can u also help me with oct/nov 2009 q14,20,27,28,30,40 plz ?

I'm so sorry. I had to go last night. And I thought you were done. :/

 

[Pwincessajwa]

that is okey tommorow i have bio and hard too

 

[Saadman]

How was the chem p12 exam!? isn't anyone eager to discuss!?