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Acids and bases question

Calculate the change in pH qhen 25cm3 of water is adddd to 10.0cm3 of a solutionof 0.100m HCl

Thanks
Original post by Ann_Onymous
Calculate the change in pH qhen 25cm3 of water is adddd to 10.0cm3 of a solutionof 0.100m HCl

Thanks


.. and your ideas are?
Reply 2
Original post by charco
.. and your ideas are?


I had an idea that everyone should be forced to wear rotating hats.

Oh sorry, maybe you weren't talking to me.
Reply 3
Original post by charco
.. and your ideas are

I first find the pH at the start so -log0.1=1 and then I find the pH at the end which I'm not sure how to do then minus the two pHs.
Its just finding the pH at the end that I am stuck on.
Reply 4
Original post by Pigster
I had an idea that everyone should be forced to wear rotating hats.

Oh sorry, maybe you weren't talking to me.


What kind though? Bowler, tophat, those one coal miners wear? And should the entire hat rotate, or just the brim, or everything but the brim? So many questions...

Original post by Ann_Onymous


I first find the pH at the start so -log0.1=1 and then I find the pH at the end which I'm not sure how to do then minus the two pHs.
Its just finding the pH at the end that I am stuck on.


How can you link the change in solution volume from adding water to the change in proton concentration?
(edited 7 years ago)
Reply 5
Original post by h3rmit
What kind though? Bowler, tophat, those one coal miners wear? And should the entire hat rotate, or just the brim, or everything but the brim? So many questions...



How can you link the change in solution volume from adding water to the change in proton concentration?


Would you do c=n/v so 35cm3 for the volume when the 25cm3 of water and the 10cm3 HCl is added together but hiw would you figure out moles.
Reply 6
Original post by Ann_Onymous
Would you do c=n/v so 35cm3 for the volume when the 25cm3 of water and the 10cm3 HCl is added together but hiw would you figure out moles.


Original post by Ann_Onymous
Would you do c=n/v so 35cm3 for the volume when the 25cm3 of water and the 10cm3 HCl is added together but hiw would you figure out moles.


The number of moles of protons is the proton concentration x the volume, do it for the 10cm^3 first then use it in the calulation with the 35cm3.

There are easier ways though, you could equate the n=cv expressions as n is the same, then find the ratios of the proton concentrations and use the expressions for pH to find the new pH. Or, you could just note the volume has increased by 35/10, so the concentration must decrease by 35/10 (or be multiplied by 10/35)
Reply 7
Original post by h3rmit
The number of moles of protons is the proton concentration x the volume, do it for the 10cm^3 first then use it in the calulation with the 35cm3.

There are easier ways though, you could equate the n=cv expressions as n is the same, then find the ratios of the proton concentrations and use the expressions for pH to find the new pH. Or, you could just note the volume has increased by 35/10, so the concentration must decrease by 35/10 (or be multiplied by 10/35)


So would it be 0.54?
Reply 8
Original post by Ann_Onymous
So would it be 0.54?


Yep
Reply 9
Original post by h3rmit
Yep


Thank you
Original post by h3rmit
What kind though? Bowler, tophat, those one coal miners wear? And should the entire hat rotate, or just the brim, or everything but the brim? So many questions...


So far, it is just an idea rather than a full blown policy.

I am working on the fine details and may publish a white paper in the summer.

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