(b) Which solution has a higher percent ionization of the acid, a 0.10M solution of HC2H3O2(aq) or a 0.010M solution of HC2H3O2(aq) ? Justify your answer including the calculation of percent ionization for each solution.

Respuesta :

Answer: The percent ionization is higher for 0.010 M solution of [tex]HC_2H_3O_2[/tex]

Explanation:

[tex]HC_2H_3O_2\rightarrow H^+C_2H_3O_2^-[/tex]

 cM           0M           0M

[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]

a) Given c= 0.10 M and [tex]\alpha[/tex] = ?

[tex]K_a=1.8\times 10^{-5}[/tex]

Putting in the values we get:

[tex]1.8\times 10^{-5}=\frac{(0.10\times \alpha)^2}{(0.10-0.10\times \alpha)}[/tex]

[tex](\alpha)=0.013[/tex]

[tex]\%(\alpha)=0.013\times 100=1.3\%[/tex]

b) Given c= 0.010 M and [tex]\alpha[/tex] = ?

[tex]K_a=1.8\times 10^{-5}[/tex]

Putting in the values we get:

[tex]1.8\times 10^{-5}=\frac{(0.010\times \alpha)^2}{(0.010-0.010\times \alpha)}[/tex]

[tex](\alpha)=0.041[/tex]

[tex]\%(\alpha)=0.041\times 100=4.1\%[/tex]

The percent ionization is higher for 0.010 M solution of [tex]HC_2H_3O_2[/tex]