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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: pandabear on March 07, 2009, 09:09:23 AM

Title: mass of NaOH
Post by: pandabear on March 07, 2009, 09:09:23 AM

What amount of solid NaOH must be added to 1.0 L of a .14 M H₂CO₃ solution to produce a solution with H⁺ = 3.2 x 10^-11?

*No significant volume change as result of the addition of the solid.

Does it matter that it is a diprotic acid? Should we set up an ICE table? I'm not sure where to start...

Title: Re: mass of NaOH
Post by: Vidya on March 07, 2009, 09:22:46 AM

I think you need to make ice table to know how much H+ ions are present there and how much out of it you want to neutralize .Calculate no of moles of NaOH required to neutralize it.
Yes take care it is diprotic.

Title: Re: mass of NaOH
Post by: Borek on March 07, 2009, 11:52:36 AM

No need for ICE table, this is a buffer question. Use Henderson-Hasselbalch equation (http://www.chembuddy.com/?left=pH-calculation&right=pH-buffers-henderson-hasselbalch).

Title: Re: mass of NaOH
Post by: Vidya on March 08, 2009, 09:13:11 AM

In Buffer solution you are using a salt and its weak acid.Than ofcourse you can use Henderson-Hasselbalch equation.But I dont think concentration of salt is given to you.A strong base and weak acid is given.

Title: Re: mass of NaOH
Post by: Borek on March 08, 2009, 09:26:33 AM

Think what reactions take place when you add NaOH. Think what you will have in the solution once pH goes up to 10.5.