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General paper discussion

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and in the last question of the paper, they asked two reasons other than the temperature or one reason, after zinc was added to coppersulfate? (I messed this question up. wrote the wrong colour change, from blue to colourless :'( )
 
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Haha not exactly. It was something like which option produces twice as much of hydrogen as compared to the equation.
Wasn't the answer to that a? The number of moles had to be twice that given in the question. If the volume remains the same and the concentration is doubled, it gives 0.04 moles while the number of moles given in the question were 0.02. Both the volume and concentration were doubled for c which would give the same number of moles as in the question
 
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Chemistry 42:
1st ques: x=7
2nd ques: Alcohol oxidized to Ethanoic Acid
MCQs: addbc
Tiration ques: R Ar=24 and was Magnesium
Salt ques: Colourless solution and ZnI2 was the formula
Graph ques: Conc=0.2mol/dm3
Iron sulphate = Green
Zinc dissolves, Blue colour fades, Pink/red/brown Copper deposit seen
In second last mcq the B part was about that magnesuim is full reacted right?
 
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how was the paper
ijlalm? Any prb then post here after 24 hours and follow the rules or else the XPC administrator will start threatning you again
 
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Well, we had to find the molar ratio between HCl and hydrogen gas which was 2:1. We had to divide 0.02 by 2 and then multiply it with 2 as twice hydrogen was produced. So the option which contained 0.02 moles was the correct answer.
But for o.02 moles of hydrogen to be produced, 0.04 moles of hcl should react :s in the equation given in the question, there were 0.02 moles of hcl and hence 0.01 moles of hydrogen na?
 
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i wrote ZnI instead of ZnI2..:cry: SHIT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! even in salt analysis, i wrote all the charges wrongt..........crap crap crap
 
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i wrote ZnI instead of ZnI2..:cry: SHIT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! even in salt analysis, i wrote all the charges wrongt..........crap crap crap
worry about the other papers now....... forget about it, you can't change anything now..... do better in p1 and 2 :) and youve got your grade
 
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worry about the other papers now....... forget about it, you can't change anything now..... do better in p1 and 2 :) and youve got your grade
i knw theres no chance of getting the mark in the final part of the question, but in the table above, if i wrote all the symbols correct just the '2' missing...will I get marks??
 
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i knw theres no chance of getting the mark in the final part of the question, but in the table above, if i wrote all the symbols correct just the '2' missing...will I get marks??
If you wrote Zinc ions and Aluminium ions (full names) then I think the examiner will consider it. If you wrote Zn ions and Al ions, I'm not so sure.
 
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i knw theres no chance of getting the mark in the final part of the question, but in the table above, if i wrote all the symbols correct just the '2' missing...will I get marks??
hmmmmmmmm m not sure, there was something mentioned about in an examiner report. check it out
 
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If you wrote Zinc ions and Aluminium ions (full names) then I think the examiner will consider it. If you wrote Zn ions and Al ions, I'm not so sure.
i wrote the symbols, then cx i wasnt sure of the charges i wrote the names...but then i saw I- at the bottom and i thought i shld better go fr symbols...so I cut the names again and wrote symbols instead.... But it was lyk dis: Zn+ Ca+ Al+3 (cx i did remember the charge fr Al
 
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Wasn't the answer to that a? The number of moles had to be twice that given in the question. If the volume remains the same and the concentration is doubled, it gives 0.04 moles while the number of moles given in the question were 0.02. Both the volume and concentration were doubled for c which would give the same number of moles as in the question
Ans was c. U had to form the second eq as well ... It was lyk dis - 2HCl+(i forgot the other reactant :p) = --- + H2 . So mole ratio is 2:1. Whereas eq in the ques was - H2SO4+ (i dont know wat) = --- + H2. Hence mole ratio here is 1:1. So originally there were 0.02 mols of hydrogen gas
 
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