chemistry mcq ans wrong?

[mickysharif]

the mcq is from 9701_s10_qp_11 question 4, the MS and ER say the ans is C, isn't it D?

 

[XPFMember]

Assalamoalaikum!!

It is C

the enthalpy changes for each reaction are as follows:

P +193

Q -244

R -340

S +410
So order=> R -> Q -> P -> S

 

[mickysharif]

Assalamoalaikum!!

It is C

the enthalpy changes for each reaction are as follows:

P +193

Q -244

R -340

S +410
So order=> R -> Q -> P -> S

Oh right thank you I understand it now. 'provide E to break, get E when make' heh, that rhymes.

Is there a chance you could also help me out with mcq no.14 from the same paper, I don't understand how to reach the answer and what knowledge i require to solve similar questions in the future.

once again thankx.

 

[XPFMember]

well that's very simple


it's actually test for halide ions...chloride ion gives white ppt. with AgNO3 which dissolves in aq. ammonia...so ans. is A

 

[mickysharif]

oh right thanks again, I forgot that totally,....... they should really write those things in the data booklet learning them is going to be a pain. can't believe i forgot it since i gave olevels.

I keep getting stuck in mcqs =/ getting really annoying....now I'm on mcq 16 from the same paper and i can't see why C can't also be the answer.. This is going to take forever.

 

[XPFMember]

btw that test is there in Halogens chapter of AS :!:

 

[soumayya]

I keep getting stuck in mcqs =/ getting really annoying....now I'm on mcq 16 from the same paper and i can't see why C can't also be the answer.. This is going to take forever.

The answer is C from the mark scheme...