1. Write the equilibrium constant expression for the third ionization of phosphoric acid (H3PO4) in water.

Question

anonymous · Answer

@emmynimmy @Hayhayz @byronichero @xlovely_Lizardx @Zarkon @hperez777 @timo86m

anonymous · Answer

imquerty, any idea?

imqwerty · Answer

:) its imqwerty 
but you can call me that too :D

okay so we have $H_3PO_4$  do you know the stepwise ionization reactions of this acid? :)

imqwerty · Answer

i can tell you in case you forgot :)

imqwerty · Answer

@CreatingMyself u there? (:

anonymous · Answer

YesYes I'm here!

anonymous · Answer

And no I only know the first ionization :(

imqwerty · Answer

okay so these are the three reactions in sequential order- http://prntscr.com/9h0ah5

imqwerty · Answer

so this how you do this question-

1st wee write the 3rd ionization reaction of $H_3PO_4$ in water->
$H_3PO_4 ^{-2}$$_{(aq)}$---------->$H^+ _{(aq)}~~+~~PO_4 ^-3_{(aq)}$

the ionic concentration is given like this->
ionic concentration =$\Large \frac{[Products]}{[Reactants]}$ 

so in out case we will have this->
ionic concentration=$\Large \frac{[H^+][PO_4 ^-3]}{[HPO_4 ^{-2}]}$ 
and this value comes equal to-> $4.8 \times 10^{-13}$

anonymous · Answer

Ahhhhh!! 
How did you calculate the ionic concentration though? what values did you substitute in place of the reactants and products?

imqwerty · Answer

well thats a general value that i remember :) i wrote that just for info
you don't have enough data in this problem to calculate that 
so in you case the answer is just this-> ionic concentration=$\Large \frac{[H^+][PO_4 ^-3]}{[HPO_4 ^{-2}]}$

anonymous · Answer

Ah so my answer ends up as

Ka=(that equation)

anonymous · Answer

Thank you! I have 3 more questions if you wouldn't mind answering them, in separate open questions of course. More medals i can give ya!

anonymous · Answer

oops not Ka
Ka is acid equilibrium

imqwerty · Answer

yeah :)
i am really sorry but i gtg now x-x i have a class and i got few hours to sleep

anonymous · Answer

Well thanks anyway man! 
Medal!

imqwerty · Answer

lol np (; buh bye :D

anonymous · Answer

get some sleep!!

imqwerty · Answer

lol i really must go but its really difficult to log off x-x os is kinda addicting