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ANYONE DOING A2 PLEASE HELP ME OUT HERE!
http://www.xtremepapers.com/community/threads/chemistry-a2-doubts.15688/
http://www.xtremepapers.com/community/threads/chemistry-a2-doubts.15688/
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http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_21.pdf
can someone pls tell me how do you know the product in q5 b(iii) "identify J" and how to draw the structural formula in c
Thanks
what are you confused about? Basically they are asking what are the products of a reaction between conc. sulfuric acid and sodium bromide, and the reaction between butanol and conc. sodium bromide.
2NaBr + 2H2SO4 -----> Na2SO4 + Br2 + 2H2O + SO2
and an alcohol can be dehydrated by a strong conc. acid into an alkene.
Please help me http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_2.pdf
question 3, d, i.
I have no idea how the answer is supposed to be to the RHS.
This one is impossible. Lead is not reduced at all in this reaction.Im not adding it.. thats what happens
It's either the one with oxygen, or this one:
PbO2 + 2 H2SO4 = 2 H2O + Pb(SO4)2
This can be possible. The question only asks for ionic equation so you don't have to worry about where the ions come from. Perhaps the some or all of the hydrogen ions are provided by another kind of acid like HCl.I'm getting:
PbO2 + 4H^(+) + SO4^(2-) + 2e- ------> PbSO4 + 2H2O
This is a perfectly balanced half equation.
But the problem with this equation is that it doesn't make sense. Sulfuric acid is a dibasic acid. This means one mole of H2SO4 will give 2 moles of H+ and one moles of sulfate ions. But here, we have 4 moles of H+ and one moles of sulfate ions. Is such a reaction possible? I don't know.
a) is PbO2 + 4H(+) + SO(2-) + 4e(-) ------> PbSO4 + 2H2Oi am re-posting this question:
1. Construct ionic half equation for:
a) PbO2(s) being reduced to PbSO4(s) in presence of of H2SO4(aq)
b) PbSO4(s) being reduced to Pb(s) in the presence of water.
c) Mow write the balanced equation for the reaction between PbO2 and lead in the presence of dilute sulfuric acid.
I also just login to ask the same ques i think solution is wrong coz the ans by my mentod is 4/9 whats ur?
Please help me http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_2.pdf
question 3, d, i.
I have no idea how the answer is supposed to be to the RHS.
no marks will not be deducted but while making a mirror image you should keep the position exactly oppI just wanted to know that when we are asked to draw a chiral compound,would the marks be deducted if I didnt draw it exactly as the way in marking scheme.Cuz almost all the times the position of 4 groups around chiral carbon in my structure are different from the structure given in marking scheme.And generally when writing structural formulae i cannot write them exactly as mentioned in marking scheme??
LiAlH4 in dry ether OR NaBH4 in water.·What reagent(s) and solvent are normally used in a laboratory to reduce a >C=O group without reducing the >C=C< group present in the same molecule?
From (b) there is 0.04 mole of ethanoic acid remaining in the equilibrium mixture.
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