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Chemistry paper 31 (NEW)

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One thing, I forgot to put the:

---( )---n after I did the nylon drawing, how much do I lose? 1 or 2 marks? And I did them with boxes too....
 
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i didn't do boxes but you should also write +h2o bcz its a condensation polymerisation
 
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nightwalker221 said:
The selenium one was that it is acting as a reducing agent because it removes the Oxygen from the what ever the reaction was. I forgot it.
i remembered a qsn in the past papers that says what type of reagent ................ so it would be an acid or a base not a reducing or an oxidising agent so i wrote a base because it is a proton acceptor but i think i'm talking about a different qsn (don't remember)
 
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AStarHunter said:
Ramosk95 said:
i didn't do boxes but you should also write +h2o bcz its a condensation polymerisation

oh man ! What did the qs say ? Cause i didn`t write h2o !
draw the structural formula of the polymer that is resulted from the following monomers but i think its not essential
 
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One thing, I forgot to put the:

---( )---n after I did the nylon drawing, how much do I lose? 1 or 2 marks? And I did them with boxes too....
 
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a qsn guys i wrote the polymer -----(oc (ch2)4conh (ch2)6nh)----n is it the same as with boxes or what??
 
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Can someone tell me the answer to

1) Which of the acid reaction is the redox reaction and the reason? (Li + HI), (Zinc Carbonate + HI) or (the one with MgO)
2) Which carboxylic acid forms when acidified potassium manganate react with Butanol? and its structural formula?

For your info, I choose:

1) One with MgO, as oxygen is involved (the explanation probably wrong) :)
2) Butanoic Acid, CH3CH2CH2COOH

Can someone confirm? :)
 
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NOOB12345 said:
Can someone tell me the answer to

1) Which of the acid reaction is the redox reaction and the reason? (Li + HI), (Zinc Carbonate + HI) or (the one with MgO)
2) Which carboxylic acid forms when acidified potassium manganate react with Butanol? and its structural formula?

For your info, I choose:

1) One with MgO, as oxygen is involved (the explanation probably wrong) :)
2) Butanoic Acid, CH3CH2CH2COOH

Can someone confirm? :)
1) I chose Lithium one since Lithium loses an electron and Hydrogen gains it.
2) I made it just like you! :)
 
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Uhmm, I put the redox one was the second carbonate reaction. As zinc was reduced to zinc iodide, and the H ion was oxidised to water..
 
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But for the second one I wrote the same thing..


I wrote for the chlorine one, a colour change from colourless to black/dark brown, and a colour change to yellowy brown.

I wrote that the Selium was the reductant, I though about writing a base, but I've only ever seen a question asking you to describe that worth 2 marks, and this one was 3, meaning 3 things were needed, so I chose that it was a reductant, as it was oxidised, and the other one was reduced, as it went from neutral charge to -1.
 
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And for the hard moles one, I wrote that the molar ratio between the metals and the hydrogen was the same with A and C, but with B it had a higher ratio, meaning a higher amount of moles and thus a large volume was produced :D
 
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I wrote for question 7b, that metal B produce more hydrogen because:

Aluminium has valency of 3 and Chlorine of 1, the formula for Aluminium Chloride is AlCl3, where as for the other 2 metals is MgCl2 and ZnCl2. Therefore 1 Mole of Aluminium will react with more moles of HCl than Zinc and Magnesium, hence producing more hydrogen.

and I wrote the same/similar for 7a where you have to identify metal and explain. Don't know if this will score me the explanation for why Metal B is Aluminium. (I heard many people explained metal B using reaction rate and oxide layer) I hope mine is an alternative answer... :p And btw why is 7a, the identification and explanation of metals only 5 marks? (I thought it would be 3 pairs of marks)

and what did you write for the explanation for the 2 other metals?
 
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