gen chem destroyer 196

[wangruoxi]

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at 37c, the Kw for H2O is 5*10^(-14), what is the pH?

It is a really simple question, X^2=5*10^(-14), the x=2.2*10^(-7)

pH around 6.6

BUT, the x here can be either OH- or H+, if we consider the OH-=2.2*10^(-7)

the answer should be bigger than 7.


Which one is correct??

 

[needzmoar]

at 37c, the Kw for H2O is 5*10^(-14), what is the pH?

It is a really simple question, X^2=5*10^(-14), the x=2.2*10^(-7)

pH around 6.6

BUT, the x here can be either OH- or H+, if we consider the OH-=2.2*10^(-7)

the answer should be bigger than 7.


Which one is correct??

You will get the same answer if you use [OH-] = 2.2E-7 just convert pOH to pH and you'll get 6.6

 

[wangruoxi]

You will get the same answer if you use [OH-] = 2.2E-7 just convert pOH to pH and you'll get 6.6

No, you will get 7.4 instead

 

[needzmoar]

No, you will get 7.4 instead

Don't forget, you have to set pKw = -log[5*10^(-14)]

 

[wangruoxi]

Don't forget, you have to set pKw = -log[5*10^(-14)]

Haha~ you are right! I forgot it CHANGES when the temp is not at 25.

Thank you!