Final answer:
The pH of 3.99 corresponds to a hydronium ion concentration of 1.02 x 10^-4 M and a hydroxide ion concentration of 9.80 x 10^-11 M in the orange.
Step-by-step explanation:
To find the concentrations of hydronium (H3O+) and hydroxide (OH-) ions in an orange with a pH of 3.99, we can use the pH definition and the ion product of water. The pH is defined as the negative logarithm of the hydronium ion concentration: pH = -log[H3O+].
Starting with the pH value, we can calculate the hydronium ion concentration as follows:
[H3O+] = 10-pH = 10-3.99 = 1.02 × 10-4 M.
To find the hydroxide ion concentration, we use the ion product of water at 25 °C, which is KW = [H3O+][OH-] = 1.0 × 10-14. From this relationship, we can calculate:
[OH-] = KW / [H3O+] = 1.0 × 10-14 M2 / (1.02 × 10-4 M)
= 9.80 × 10-11 M.
Therefore, the concentrations in an orange with a pH of 3.99 are:
- [H3O+] = 1.02 × 10-4 M
- [OH-] = 9.80 × 10-11 M.