Question

Aspirin, which is acetylsalicylic acid, is the most common over the counter pain killer. Over 15 billion tablets of aspirin are sold annually. If a solution of aspirin has a [OH-] = 4.4 x 10–¹² M, what is the pH of the solution?

a. 11.36
b. -2.64
c. 5.8
d. 2.64
e. -11.36

Answer 1

The pH of the aspirin solution with a hydroxide ion concentration of 4.4 x 10–¹² M is calculated to be 2.64 using the relationship between pOH and pH.

Step-by-step explanation:

If a solution of aspirin has a [OH-] of 4.4 x 10–¹² M, we first need to find the pOH of the solution, which is given by the negative logarithm (base 10) of the hydroxide ion concentration:

pOH = -log[OH-] = -log(4.4 x 10–¹²) = 11.36

The pH can be found by using the relationship pH + pOH = 14 (at 25°C).

pH = 14 - pOH = 14 - 11.36 = 2.64

Therefore, the pH of the solution is 2.64, which matches option d.