Answer: a) 1.4 %
b) 48%
Explanation:
[tex]C_7H_6O_2\rightarrow H^+C_7H_5O_2^-[/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]
a) Given c= 0.32M and [tex]K_a=6.3\times 10^{-5}[/tex]
[tex]\alpha[/tex] = ?
Putting in the values we get:
[tex]6.3\times 10^{-5}=\frac{(0.32\times \alpha)^2}{(0.32-0.32\times \alpha)}[/tex]
[tex](\alpha)=0.014[/tex]
[tex]\%(\alpha)=0.014\times 100=1.4\%[/tex]
b) Given c= 0.00014 M and [tex]K_a=6.3\times 10^{-5}[/tex]
[tex]\alpha[/tex] = ?
Putting in the values we get:
[tex]6.3\times 10^{-5}=\frac{(0.00014\times \alpha)^2}{(0.00014-0.00014\times \alpha)}[/tex]
[tex](\alpha)=0.48[/tex]
[tex]\%(\alpha)=0.48\times 100=48\%[/tex]
