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Titration/Maximum Solubility Question, Help? (Attachced)

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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Reply 1

charco

Study Forum Helper

Original post by chrlhyms

"the most that will dissolve"

This is basically a units convertion question.

"What is x mol dm^-3 expressed in ppm?"

Reply 2

username2174765

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?

Reply 3

charco

Study Forum Helper

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.

Reply 4

username2174765

Original post by charco

You need the density to calculate the mass of 1 litre of solution.

How would I do that?

Reply 5

charco

Study Forum Helper

Original post by chrlhyms

How would I do that?

density is mass per unit volume

Reply 6

username2174765

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