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# Titration/Maximum Solubility Question, Help? (Attachced) watch

1. Hi,
I am a bit confused about how to approach this question as the mark scheme uses methods which I do know. However, am unsure what to do with the "maximum solubility" and how to approach it.

Thanks
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2. (Original post by chrlhyms)
Hi,
I am a bit confused about how to approach this question as the mark scheme uses methods which I do know. However, am unsure what to do with the "maximum solubility" and how to approach it.

Thanks
"the most that will dissolve"

This is basically a units convertion question.

"What is x mol dm-3 expressed in ppm?"
3. (Original post by charco)
"the most that will dissolve"

This is basically a units convertion question.

"What is x mol dm-3 expressed in ppm?"
I see, do I not need to use the density at all?
4. (Original post by chrlhyms)
I see, do I not need to use the density at all?
You need the density to calculate the mass of 1 litre of solution.
5. (Original post by charco)
You need the density to calculate the mass of 1 litre of solution.
How would I do that?
6. (Original post by chrlhyms)
How would I do that?
density is mass per unit volume
7. (Original post by charco)
density is mass per unit volume
I'm still confused, so is this right:

You want the value in grams and 1x10^-6 =1ppm,
so 2.8x10^-4 x 32 (Mr of O2) = 8.96x10^-3g/dm^3

and as 1dm^3=1000g
8.96x10^-3/1000 = 9x10^-6g therefore = 9ppm?

Is this method correct? As the answer is 9
8. bump

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