Calculate the percent dissociation of 4-chlorobutanoic acid C3H6ClCO2H in a 0.54mM aqueous solution of the stuff. You may find some useful data in the ALEKS Data resource. Round your answer to 2 significant digits.

Respuesta :

Answer: The percent dissociation of 4-chlorobutanoic acid is 21%

Explanation:

The dissociation of weak acid is shown as:

[tex]C_3H_6ClCOOH\rightarrow C_3H_6ClCOO^-+H^+[/tex]

          cM              0             0

         [tex]c-c\alpha[/tex]        [tex]c\alpha[/tex]         [tex]c\alpha[/tex]

So dissociation constant will be:

[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]

Give c= 0.54 mM = [tex]5.4\times 10^{-4}M[/tex] and [tex]\alpha[/tex] = ?

[tex]K_a=3.02\times 10^{-5}[/tex]

Putting in the values we get:

[tex]3.02\times 10^{-5}=\frac{(5.4\times 10^{-4}\times \alpha)^2}{(5.4\times 10^{-4}-5.4\times 10^{-4}\times \alpha)}[/tex]

[tex](\alpha)=0.21[/tex]

[tex]\%(\alpha)=0.21\times 100=21\%[/tex]

Thus the percent dissociation of 4-chlorobutanoic acid is 21%