Answer: 1.05
Explanation:
On ionization, hydrobromic acid completely dissociates into hydrogen ion and bromine ion. The equation is stated below
HBr <--> H+ + Br-
Recall that pH = - log(H+)
Concentration of hydrogen ion (H+) = 0.09M
So, pH = - log (0.09)
pH = - (-1.05)
pH = 1.05
The pH of 0.09M solution of HBr is 1.05. Thus, it is highly acidic.