Question

Calculate the pH of a solution that results from mixing 44.7 mL of 0.165 M ammonia with 22.6 mL of 0.109 M ammonium chloride.
The Kb value for NH3 is 1.8 x 10-5.

Answer 1

What is the buffer component ratio, ([NO2-]/[HNO2]) of a nitrite buffer that has a pH of 3.98. Ka of HNO2 is 7.1 x 10-4.


For this one ^^ I tried base10^-3.98 divided by the ka to get concentration but....

Answer 2

And the problem for the NH3 Nh4 problem i dont know if i set up a start change AN chart after finding new concentrations.

Answer 3

@pengembara_bumi1

Answer 4

hold on :)

Answer 5

@Frostbite @Krishnadas @dumbsearch2

Answer 6

Sounds like a Henderson-Hasselbalch problem.

Answer 7

But the things is, Im not supposed to use that equation! :/ Im supposed to set up a reaction and etc and use the ka to find concentrartion of poh then ph (for the nh3 nh4 problem)

Answer 8

buttt I dont know what type of reaction im supposed to go off of. is it NH3 +h20 <--> OH- + NH4

Answer 9

or NH3+NH4 or ....??

Answer 10

ok i will try that

Answer 11

Ka? Usually ahaha.

Answer 12

@jennilalala : look at the equations i had given :) mybe it can help u

Answer 13

so what i did was

Answer 14

im not supposed to use those though @pengembara_bumi1

Answer 15

i got ph as 8.95 :/

Answer 16

Sorry me saying some rubbish. We use another good old relation:
\[NH _{3}+H _{2}O \rightarrow NH _{4}^{+}+OH ^{-}\]
\[K _{b}=\frac{ [NH _{4}^{+}] [OH ^{-}] }{ [NH _{3}] }\]
Try use that instead.

Answer 17

Find the hydroxide concentration and use water's self ionization constant to find the proton concentration then take the negative logarithm to find the pH. Use the constant for water at 25 degrees C.

Answer 18

so i just use ice chart instead?

Answer 19

ice chart? I see no need for that?

Answer 20

Do you mind doing a walk through of the problem when you have the time? i think im confusing myself