Debrief -> Pure Chemistry!
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Discuss the questions here!
To be open at 4.15pm -
It's opened!
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easy paper, only got some careless mistake here and there, like the one with ethanoic acid react with calcium carbonate, i forgot about CH3COO- (-ve charge) and that is Ca(CH3COO)2
zzz
then got the one about salt conducting electricity, its supposed to be mobile IONS and not mobile ELECTRONS.
zzz
other than that, easy paper -
Hoho. Paper was damn easy. But well, guess moderation will pull up the A1 grade again. Let's say...A1= 80%?!
LOL. -
Originally posted by thehappybunny:
huh?! That's the ans? (salt)
easy paper, only got some careless mistake here and there, like the one with ethanoic acid react with calcium carbonate, i forgot about CH3COO- (-ve charge) and that is [b]Ca(CH3COO)2
zzz
then got the one about salt conducting electricity, its supposed to be mobile IONS and not mobile ELECTRONS.
zzz
other than that, easy paper
[/b] -
the part about methane and pollution problem, what is it?
Global warming is NOT a pollution.
Overall is was quite ok.
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i wrote ionic eqn leh cos i don know how to write e full eqn. so correct or wrong?Originally posted by thehappybunny:easy paper, only got some careless mistake here and there, like the one with ethanoic acid react with calcium carbonate, i forgot about CH3COO- (-ve charge) and that is Ca(CH3COO)2
zzz
then got the one about salt conducting electricity, its supposed to be mobile IONS and not mobile ELECTRONS.
zzz
other than that, easy paper -
yeah, according to my friends thats the answer, but some of them cant balance the eqn. since its a metal carbonate, there will be salt, water and carbon dioxideOriginally posted by masterofIT:huh?! That's the ans? (salt) -
Lol. I didn't balanced it either. 2 marks gone.Originally posted by thehappybunny:yeah, according to my friends thats the answer, but some of them cant balance the eqn. since its a metal carbonate, there will be salt, water and carbon dioxide -
Methane ah.. i wrote something like that. My friends say methane has a variety of answers and that cambrige won't be that strict when it comes to marking.
Methane, source -> decomposition of baterial matters.
Methane, pollution -> methane will lead to greenhouse warming which will increase the global temperature.
Weak ans though. Lol. -
lol. i thought methane was a natural gas then i put the source of methane as 'Farms.'
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Green house gases is pollution meh? i wrote incomplete combustion of methane produces pollutants
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isnt it (CH3COO)2CaOriginally posted by thehappybunny:easy paper, only got some careless mistake here and there, like the one with ethanoic acid react with calcium carbonate, i forgot about CH3COO- (-ve charge) and that is Ca(CH3COO)2
zzz
then got the one about salt conducting electricity, its supposed to be mobile IONS and not mobile ELECTRONS.
zzz
other than that, easy paper -
Incomplete combustion of methane???Originally posted by rain-coat:Green house gases is pollution meh? i wrote incomplete combustion of methane produces pollutants
Produce pollutant???
CH4 + 2O2 --> CO2 + 2H2O
methane almost always undergoes complete combustion. No pollutant except CO2. -
Why the paper so easy one?
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Incomplete combustion also produce Soot(Unburnt Carbon) and Carbon monoxide.Originally posted by ultranova3:Incomplete combustion of methane???
Produce pollutant???
CH4 + 2O2 --> CO2 + 2H2O
methane almost always undergoes complete combustion. No pollutant except CO2. -
What will be the equation??Originally posted by Darkness_hacker99:Incomplete combustion also produce Soot(Unburnt Carbon) and Carbon monoxide.
CH4 + O2 --> C + 2H2O???
CH4 + O2 --> CO + H2O ???
It is very unlikely, even in limited oxygen for methane to burn incompletely.
Those that usually undergoes incomplete combustion are those with long carbon chain. Some more CH4 is a gas and highly flammable.
Btw, methane can trap IR and contribute to global warming. -
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eh........suprising easy
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NNb, i failed my pure chem 4 years ago.
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Chem ah....as always i'll aim for a pass
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knnn, but really ah
why today's paper so easy?
i was expecting a much harder one -
easy ppl complainOriginally posted by mrcoconut:knnn, but really ah
why today's paper so easy?
i was expecting a much harder one
hard parents complain
Sgreans just like to complain -
it really depends on who's perspective you are taking. If you are a good student(as in good at your studies) you want hard papers otherwise every one gets high marks and you cannot excel.Originally posted by eagle:easy ppl complain
hard parents complain
Sgreans just like to complain
on the other hand, the average and lousier students want easier papers so that they can get confused with the good ones -
wan easy...so everybody can passOriginally posted by hisoka:it really depends on who's perspective you are taking. If you are a good student(as in good at your studies) you want hard papers otherwise every one gets high marks and you cannot excel.
on the other hand, the average and lousier students want easier papers so that they can get confused with the good ones