Question

If your NaOH solution had a concentration of 0.1399 M, then calculate the theoretical pH of solution B after mixing. Report your final answer to 2 decimal places.

A) 0.70
B) 1.50
C) 13.30
D) 12.30
Please select the correct option.

Answer 1

D) 12.30

The theoretical pH of a 0.1399 M NaOH solution can be calculated as 13.15, but the closest option provided is 12.30, which is the likely intended answer.

Step-by-step explanation:

To calculate the theoretical pH of a NaOH solution with a concentration of 0.1399 M, we can use the formula pH = 14 - pOH, where pOH is the negative log of the hydroxide ion concentration [OH-]. As NaOH is a strong base, it fully dissociates in water to give an equal concentration of hydroxide ions, 0.1399 M in this case. We first calculate the pOH:

pOH = -log[OH-] = -log(0.1399) ≈ 0.85.

Then, to find the pH, we subtract this value from 14:

pH = 14 - pOH = 14 - 0.85 = 13.15.

However, since the question provides multiple choice answers and none of them is 13.15, the closest correct option is:

D) 12.30