Chemstry acid- base titration


label Chemistry
account_circle Unassigned
schedule 1 Day
account_balance_wallet $5

What is the pH at the equivalence point in the titration of 20.0 mL of 0.200 M HA with 0.200 M NaOH? The Ka for HA is 7.07×10−6 .

Feb 27th, 2015

here the number of equivalen of the acid is:

4*10^(-3), so we  have to require that the base has 4*10^(-3) number of equivalent, so the volume of the added base is:

(0.2/1000)*V = 4*10^(-3)

and then:

V = 20 mL

so the concentration of the resultant salt Cs is:

Cs= (4*10^(-3))/(40*10^(-3)) = 0.2 N

then the [OH-] concentration of our solution is:

[OH-] = sqrt(Kw Cs/Ka) = sqrt(10^(-14)*0.1/ (7.07*10^(-6)) = 1.19*10^(-5)

so the pOH = 4.92 and pH = 14- 4.92 = 9.08

please note that Kw is the ionic product of the water

Feb 27th, 2015

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Feb 27th, 2015
...
Feb 27th, 2015
Nov 17th, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer