Question

Physiological pH (7.4) is the average pH of blood. Which of the following is a reasonable hydrogen ion concentration of a solution at physiological pH?

1) -7.4 M
2) 0.6 M
3) 6 x 10⁻⁷ M
4) 1 x 10⁻⁸ M
5) 4 x 10⁻⁸ M

Answer 1

The reasonable hydrogen ion concentration of a solution at physiological pH (7.4) is 3) 6 x 10⁻⁸ M, which corresponds to the pH value being slightly more alkaline than neutral.

Step-by-step explanation:

The question relates to the calculation of the hydrogen ion concentration of a solution at a given pH, in this case, physiological pH (7.4). The pH scale is logarithmic, meaning that a change in one pH unit reflects a tenfold change in hydrogen ion concentration.

The pH of a solution is calculated using the negative logarithm of the hydrogen ion concentration (pH = -log[H+]). Thus, a solution with a pH of 7 has a hydrogen ion concentration of 1.0 x 10-7 M. Given physiological pH of 7.4 for blood, which is slightly alkaline, options 1, 2, 4, and 5 can be eliminated because they are not consistent with the pH value.