Answer:
0.007 M
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
[tex]pH=-log(\sqrt{k_a\times C})[/tex]
Where, C is the concentration = ?
Given, pH = 3.45
So, for [tex]CH_3COOH[/tex], [tex]K_a=1.8\times 10^{-5}[/tex]
[tex]3.45=-log(\sqrt{1.8\times 10^{-5}\times C})[/tex]
[tex]\log _{10}\left(\sqrt{1.8\cdot \:10^{-5}C}\right)=-3.45[/tex]
C = 0.007 M
