Value of Kw

Acidity
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hojae_lee_1C
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Value of Kw

Postby hojae_lee_1C » Sun Jul 30, 2017 10:42 am

The value of Kw for water at body temperature (37°C) is 2.1 X 10^-14. (a)What is the molarity of H3O+ ions and the pH of neutral water at 37°C? (b) What is the molarity of OH- in neutral water at 37"C?

How would I approach part (a) and (b)?

Sarah_Wilen
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Joined: Fri Jun 23, 2017 11:39 am
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Re: Value of Kw

Postby Sarah_Wilen » Sun Jul 30, 2017 12:14 pm

The value of Kw for water at body temperature (37°C) is 2.1 X 10^-14. (a)What is the molarity of H3O+ ions and the pH of neutral water at 37°C? (b) What is the molarity of OH- in neutral water at 37"C?

How would I approach part (a) and (b)?

Notice that the value of Kw shifted from 1.0 x 10^-14 at 25°C to its new Kw at 37"C: 2.1 X 10^-14. Now that we've noticed it, we can continue.

1) I start by writing out the equation of water's dissociation in water.


2) I write out my Kw equation and solve for the concentrations of hydronium and hydroxide by squaring both sides.





3) Now, we solve for the pH just how we always would. (negative log)


yay


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