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OCR Equilirium question.

Can anyone explain this question? I've been attempting it for a while and i don't understand why the values need to be multiplied by 5 and not divided by 2? Can someone xplain?
(edited 8 years ago)
Reply 1
Original post by AqsaMx
Can anyone explain this question? I've been attempting it for a while and i don't understand why the values need to be multiplied by 5 and not divided by 2? Can someone xplain?


Firstly, why do you think you are dividing by 2?

As for the multiplication by 5, I don't see how that fits in.
Reply 2
Original post by RMNDK
Firstly, why do you think you are dividing by 2?

As for the multiplication by 5, I don't see how that fits in.


The mark scheme says that you need to multiply by 5 which is what I don't understand. I thought that you divide the values by 2 as that's the volume but I may be wrong :|
Reply 3
Original post by AqsaMx
The mark scheme says that you need to multiply by 5 which is what I don't understand. I thought that you divide the values by 2 as that's the volume but I may be wrong :|



You're right. To get concentration you divide moles by volume.

But what's the units of volume?

Spoiler

The volume they give you is 200cm3
How do you convert that to the new units?

I really don't see why the multiplying by 5 is necessary..
Reply 4
Original post by RMNDK
You're right. To get concentration you divide moles by volume.

But what's the units of volume?

Spoiler

The volume they give you is 200cm3
How do you convert that to the new units?

I really don't see why the multiplying by 5 is necessary..


Ohh.. Oops. It's meant to be 0.2. Dividing by 0.2 and t.multiplying my five is equivalent so it makes sense now :3

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