The ph of a popular soft drink is 3.4; what is its hydronium ion concentration?

Answer is: 4·10⁻⁴ M.

pH (soft drink) = 3,4. This drink is acidic.

c (H₃O⁺) = ? - concentration of hydronium ion.

pH = - log c (H₃O⁺) ⇒ c (H₃O⁺) = 10∧-pH.

c (H₃O⁺) = 10⁻³·⁴.

c (H₃O⁺) = 4·10⁻⁴ M (mol/dm³).

pH (potential of hydrogen) i s a numeric scale used to define the acidity or basicity of an aqueous solution.