What is the PH of a 1.3×(10)^-9 M HBr solution?

pH solution = 8.89

Given

The concentration of HBr solution = 1.3 x 10⁻⁹ M

Required

the pH

Solution

HBr = strong acid

General formula for strong acid :

[H⁺]= a . M

a = amount of H⁺

M = molarity of solution

HBr⇒H⁺ + Br⁻⇒ amount of H⁺ = 1 so a=1

Input the value :

[H⁺] = 1 x  1.3 x 10⁻⁹

[H⁺] = 1.3 x 10⁻⁹

pH = - log [H⁺]

pH = 9 - log 1.3

pH = 8.89

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.