Final answer:
The hydroxide ion concentration in a gastric juice solution with a pH of 2 is 1.0 × 10^-12 M, calculated using the ion product of water at 25°C, which is 1.0 × 10^-14 M.
Step-by-step explanation:
The gastric juices in the stomach have a pH of approximately 2, which indicates a high concentration of hydronium ions (H3O+) due to the acidic nature of the environment. To find the hydroxide ion (OH-) concentration in this solution, we can use the relation that the product of hydronium ion concentration and hydroxide ion concentration is a constant at a given temperature, known as the ion product of water (Kw).
At 25°C, Kw is approximately 1.0 × 10-14. Since the pH is 2, the hydronium ion concentration is 10-2 M, and thus we can calculate:
Kw = [H3O+][OH-]
1.0 × 10-14 = (10-2 M)([OH-])
To find the hydroxide ion concentration, you divide Kw by the hydronium ion concentration:
[OH-] = × 10-14 M / 10-2 M = 1.0 × 10-12 M
The hydroxide ion concentration in a solution with a pH of 2 is 1.0 × 10-12 M.