Answer
a. HBr is a strong acid and concentration of $H_{3}O$+ is the same as HBr. Therefore [$H_{3}O$+] = 1.7 M.
b. $HNO_{3}$ is a strong acid and concentration of $H_{3}O$+ is the same as $HNO_{3}$. Therefore [$H_{3}O$+]= 1.5 M.
c. Carbonic acid is a weak acid. So, the concentration of $H_{3}O$+ is less than $H_{2}CO_{3}$. Therefore [$H_{3}O$+] < 0.38M
d. Formic acid is a weak acid. So, the concentration of $H_{3}O$+ is less than HCOOH. Therefore [$H_{3}O$+] < 1.75M.
Work Step by Step
a. HBr is a strong acid and concentration of $H_{3}O$+ is the same as HBr. Therefore [$H_{3}O$+] = 1.7 M.
b. $HNO_{3}$ is a strong acid and concentration of $H_{3}O$+ is the same as $HNO_{3}$. Therefore [$H_{3}O$+]= 1.5 M.
c. Carbonic acid is a weak acid. So, the concentration of $H_{3}O$+ is less than $H_{2}CO_{3}$. Therefore [$H_{3}O$+] < 0.38M
d. Formic acid is a weak acid. So, the concentration of $H_{3}O$+ is less than HCOOH. Therefore [$H_{3}O$+] < 1.75M.
