What are the concentrations of hso4−, so42-, and h+ in a 0.35 m khso4 solution? (hint: h2so4 is a strong acid; ka for hso4− = 1.3 ✕ 10−2.)?

Respuesta :

Answer;

[H+] = 0.051 M

[SO4=] = 0.051M  

[HSO4-] = 0.16M

Explanation;

HSO4- <==> H+ + SO4= ..... Ka = 1.3x10^-2

Ka = [H+] [SO4=] / [HSO4-]  

1.3x10^-2 = x^2 / (0.21-x)  

Using algebra and solving the quadratic equation to solve for x.  

x = 0.051  

Therefore;

[H+] = [SO4=] = 0.051M  

[HSO4-] = 0.16M

Answer : The concentration of [tex]HSO_4^-[/tex], [tex]SO_4^{2-}[/tex] and [tex]H^+[/tex] are 0.29 M, 0.061 M and 0.061 M respectively.

Explanation :

First we have to calculate the concentration of [tex]HSO_4^-[/tex]

The dissociation of [tex]KHSO_4[/tex] is:

[tex]KHSO_4\rightarrow K^++HSO_4^-[/tex]

As, 1 mole of [tex]KHSO_4[/tex] gives 1 mole of [tex]HSO_4^-[/tex]

So, 0.35 M of [tex]KHSO_4[/tex] gives 0.35 M of [tex]HSO_4^-[/tex]

Now we have to determine the concentration of [tex]SO_4^{2-}[/tex] and [tex]H^+[/tex].

The dissociation of [tex]HSO_4^-[/tex] is:

                          [tex]HSO_4^-\rightleftharpoons H^++SO_4^{2-}[/tex]

Initial conc.      0.35           0       0

At eqm.          (0.35-x)        x        x

The expression of acid dissociation constant will be:

[tex]K_a=\frac{[H^+][SO_4^{2-}]}{[HSO_4^-]}[/tex]

Now put all the given values in this expression, we get:

[tex]1.3\times 10^{-2}=\frac{(x)\times (x)}{(0.35-x)}[/tex]

[tex]x=0.061M[/tex]

Thus, the concentration of [tex]SO_4^{2-}[/tex] = x = 0.061 M

The concentration of [tex]H^+[/tex] = x = 0.061 M

The concentration of [tex]HSO_4^-[/tex] = 0.35 - x = 0.35 - 0.061 = 0.29 M