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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: MarinaSchnider on March 16, 2020, 04:14:46 PM

Title: Volumes for pH adjustment
Post by: MarinaSchnider on March 16, 2020, 04:14:46 PM
How do I calculate the volume of KOH 50% to be added into a pH=4 solution in a volume of 1 liter in order to raise the solution's pH to pH=6?
Title: Re: Volumes for pH adjustment
Post by: chenbeier on March 16, 2020, 04:30:33 PM
Calculate the H+ concentration for both pH.
Then calculate the difference of them. This is amount what has to be neutralized.
Then you have to figure out what is the concentration in 50% Solution KOH and work it out.
The problem is, what kind of acid do you have. Some work as buffer.
Title: Re: Volumes for pH adjustment
Post by: MarinaSchnider on March 16, 2020, 04:34:05 PM
The acid is unknown...
Title: Re: Volumes for pH adjustment
Post by: Borek on March 16, 2020, 06:15:32 PM
How do I calculate the volume of KOH 50% to be added into a pH=4 solution in a volume of 1 liter in order to raise the solution's pH to pH=6?

The acid is unknown...

Not enough information then (unless you are expected to assume it is a strong acid, 100% dissociated).