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Edexcel Chemistry Unit 1 15th May

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Reply 160
Avatar for verdikt
verdikt
Can anyone explain Jun 2010, Qn 10? Why does the MS suggest C?

10 Which of these solutions does not contain the same total number of ions as the others?
A 10.00 cm
3
of 0.100 mol dm
−3
NaCl(aq)
B 20.00 cm
3
of 0.050 mol dm
−3
NaCl(aq)
C 20.00 cm
3
of 0.050 mol dm
−3
MgCl
(aq)
D 13.33 cm
3
of 0.050 mol dm
−3
MgCl
2
2
(aq)
Original post by YellowAndBlack
Cheeky chirpse there hahah :wink:


:rofl:
Original post by verdikt
Can anyone explain Jun 2010, Qn 10? Why does the MS suggest C?

10 Which of these solutions does not contain the same total number of ions as the others?
A 10.00 cm
3
of 0.100 mol dm
−3
NaCl(aq)
B 20.00 cm
3
of 0.050 mol dm
−3
NaCl(aq)
C 20.00 cm
3
of 0.050 mol dm
−3
MgCl
(aq)
D 13.33 cm
3
of 0.050 mol dm
−3
MgCl
2
2
(aq)


Work out the number of moles in each and then multiply that by the number of ions in each molecule (you don't need to multiply by Avogadro's constant as it would just cancel with the others). You should see why the answer is C! :smile:
Original post by TenaciousMonkey
Yeah, 'cause I spend my time trying to get girls from TSR by seducing them with chemistry revision :P


:wink: You, I, and the rest of the world knew what you were thinking :colondollar:
You start with chemistry ... and soon you'll be discussing biology :wink:
COCK IN SON
Original post by YellowAndBlack
:wink: You, I, and the rest of the world knew what you were thinking :colondollar:
You start with chemistry ... and soon you'll be discussing biology :wink:
COCK IN SON


What can I say? You got me.
Reply 165
Avatar for Fisheh
Fisheh
this isnt revision.

GOD
Original post by Fisheh
this isnt revision.

GOD


May be it might help :P
Reply 167
Avatar for Ricky1995
Ricky1995
Anybody hazard a guess at what experiment we may have to draw out?
Original post by Ricky1995
Anybody hazard a guess at what experiment we may have to draw out?


Something floating in acid collecting a gas of some description, thats a favourite and also very easy to mock. :smile:
Reply 169
Avatar for fifty_six
fifty_six
can sum1 help me with mechanism drawing and curly arrows
Original post by fifty_six
can sum1 help me with mechanism drawing and curly arrows


What do you need to know in particular?
Usually it is unit 1 chemistry that is the hardest, luckily I got away with it in my first go.

Any way I can help you guys out?
Reply 172
Avatar for fifty_six
fifty_six
Original post by TenaciousMonkey
What do you need to know in particular?


Show, in full, the mechanism for this reaction in which ethene is converted to
chloroethane.
Reply 173
Avatar for fifty_six
fifty_six
Original post by UserInvalid
Usually it is unit 1 chemistry that is the hardest, luckily I got away with it in my first go.

Any way I can help you guys out?


help is really needed .. :smile:
impo topic
Original post by fifty_six
help is really needed .. :smile:
impo topic


go ahead and ask.
Reply 175
Avatar for fifty_six
fifty_six
Original post by UserInvalid
go ahead and ask.


how to handle MCQs and hesses law
Original post by fifty_six
how to handle MCQs and hesses law


I didn't get what you mean by MCQ :s-smilie:

but for hesses, remember you need to know the defination clearly to be able to solve it.

it is just like solving vectors, there are two directions you can solve the question, one is always unknown and the other is known. Sometimes you will have to turn the arrow, and when you turn the arrow the, if it is exo- (negative) it becomes endo (positive), vice versa.

Remember the definations, that is the key to solve it. And sometimes remember, they add 2 moles instead of 1 in the reaction equation, so you just simply multiply the enthalpy by two.
Original post by fifty_six
how to handle MCQs and hesses law


In my opinion after having done a billion multiple choice questions in the various past papers is don't look for the right answer straight away unless its blazingly obvious. :wink:

Some of them require you to think outside of the box so look at the question and attack it logically, elimate answers that it can't possibly be and if you are left with a 50% chance between two final answers at least thats betters than a 25% with 4.
(edited 11 years ago)
Reply 178
Avatar for fifty_six
fifty_six
Original post by HarryMWilliams
In my opinion after having done a billion multiple choice questions in the various past papers is don't look for the right answer straight away unless its blazingly obvious. :wink:

Some of them require you to think outside of the box so look at the question and attack it logically, elimate answers that it can't possibly be and if you are left with a 50% chance between two final answers at least thats betters than a 25% with 4.


thank u .. i hope this will help. what other topic i need to knw..
Reply 179
Avatar for Ricky1995
Ricky1995
"Explain why stereoisomerism can occue in alkenes, and why hex-2-ene has stereoisomers but hex-1-ene does not." (2)

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