Answer:
(a) 1.6 x 10⁻⁵ M
(b) 0.20 M
(c) 4.0x 10⁻⁸ M
(d) 7.9 x 10⁻⁹ M
Explanation:
The pH value is the negative logarith of the concentration of hydronium ions in solution:
pH = - log[H₃O⁺]
so to convert the given pHs in this question to molar concentration of H₃O⁺, we need to take the inverse logarhitmic function of minus pH.
(a) pH (urine) = 4.8
inverse log (- 4.8 ) = 10^(-4.8) = 1.6 x 10⁻⁵
[H₃O⁺] urine = 1.6 x 10⁻⁵ M
(b) pH (stomach fluid) =0.7 M
inverse log (-0.7) = 10^(-0.7) = 0.20
[H₃O⁺] stomach fluid = 0.20 M
(c) pH (blood) = 7.4
inverse log (-7.4) = 10^(-7.4) =4.0x 10⁻⁸
[H₃O⁺] blood = 4.0x 10⁻⁸ M
(d) pH (pancreatic ) = 8.1
inverse log (-8.1) = 10^(-8.1) = 7.5 x 10⁻⁹
[H₃O⁺] pancreatic = 7.9 x 10⁻⁹ M
