Biology; Chemistry; Physics: Post your doubts here!

[papajohn]

http://papers.xtremepapers.com/CIE/...l O Level/Chemistry (5070)/5070_s12_qp_21.pdf
Please Q9 a and b..

 

[usama321]

9a, if the temperature is increased the equilibrium would shift to the right as the reaction is endothermic

b the forward reaction would increase. Remember the question is asking about the collisions of the reacting particles only. This is so because as there would be less volume, there would be more frequent collisions and the forward reaction would increase.(The thing is the backward reaction would increase more, because there are more moles in the products. but the question only asks about the forward reaction )

 

[Buland Iqbal]

I m sure answer of mark scheme is wrong. try it and tell me the answer please:
View attachment 26529

Buland Iqbal Saad Mughal usama321 asma tareen robinhoodmustafa

450 cm3 is the answer.

 

[papajohn]

9a, if the temperature is increased the equilibrium would shift to the right as the reaction is endothermic

b the forward reaction would increase. Remember the question is asking about the collisions of the reacting particles only. This is so because as there would be less volume, there would be more frequent collisions and the forward reaction would increase.(The thing is the backward reaction would increase more, because there are more moles in the products. but the question only asks about the forward reaction )

You simply rock!

 

[asma tareen]

I m sure answer of mark scheme is wrong. try it and tell me the answer please:
View attachment 26529

Buland Iqbal Saad Mughal usama321 asma tareen robinhoodmustafa

i)aqueous solid,liquid,gas
ii)moles of HCl 25/1000*1.5=0.0375
moles of CO2=1:2
x:0.0375
x=0.0375/2=0.01875 mol
vol=o.o01875*24000=45ocm3
i guess whts the ans in marking schemes

 

[sourov97]

somebody pls explain this.

 

[papajohn]

Is that O level question??

 

[sourov97]

pls explain this!

 

[usama321]

Is that O level question??

yup it is, i am confused about it too what do you say Saad Mughal

 

[usama321]

yup it is, i am confused about it too what do you say Saad Mughal

talking about this one

View attachment 26546
somebody pls explain this.

 

[sourov97]

Is that O level question??

yes! related to macromolecule or condensation polymerisation!

 

[usama321]

View attachment 26548
pls explain this!

i think the answer would be B. When it is added to HNO3 no reaction would happen on the other hand when added to HCl, a white precipitate of AgCl would form

 

[ZaqZainab]

i think the answer would be B. When it is added to HNO3 no reaction would happen on the other hand when added to HCl, a white precipitate of AgCl would form

What about D when added to HNO3 No reaxtion but which HCL effervescence!

 

[sourov97]

talking about this one

guys..clearly u have not done june 12 paper 1s

 

[usama321]

View attachment 26546
somebody pls explain this.

i think for this the answer i C because, the first monomer can give H from both sides and react with the OH on both sides
the second monomer can react from the right hand side with its hydrogen, but the COOH on the left won't react with the COOH and thus it won't form a chain
the other two are just like the first one, there H would react with the OH

 

[usama321]

What about D when added to HNO3 No reaxtion but which HCL effervescence!

nope., HNO3 is an acid too, so there would be effervescence with this one too

guys..clearly u have not done june 12 paper 1s

not knowing the explaination for an answer does not mean you have not done the question. I knew the answer, and i was thinking about asking the reasoning from someone

 

[sourov97]

i think the answer would be B. When it is added to HNO3 no reaction would happen on the other hand when added to HCl, a white precipitate of AgCl would form

what about A....BaCl2 would not react with HCl but with HNO3 ?

 

[ZaqZainab]

i think for this the answer i C because, the first monomer can give H from both sides and react with the OH on both sides
the second monomer can react from the right hand side with its hydrogen, but the COOH on the left won't react with the COOH and thus it won't form a chain
the other two are just like the first one, there H would react with the OH

Exactly i would go for C too

 

[usama321]

what about A....BaCl2 would not react with HCl but with HNO3 ?

There would be no observation, as nitrate salts are soluble

 

[sourov97]

i think for this the answer i C because, the first monomer can give H from both sides and react with the OH on both sides
the second monomer can react from the right hand side with its hydrogen, but the COOH on the left won't react with the COOH and thus it won't form a chain
the other two are just like the first one, there H would react with the OH

rection with 1st and last monomers gives nylon and terelyne.....the second monomer is amino acid which combines with itself to form protein...
but what is the third one?