Question

Which HNO3 solution yields a pH of 4.8?

a. 0.0033 M

b. 0.000015 M

c. 0.00035 M

d. No right answer.

e. 0.00000050 M

Answer 1

The answer is B, HNO3 solution of 0.000015 M yields a pH of 4.8.

Step-by-step explanation:

The equation to find the pH of a solution is the following:

`ph = - log( {h}^( + ) )`

Since HNO3 is a strong acid, it almost 100% dissociates according to a 1:1 molar ratio, into hydrogen cations and nitrate anions, meaning the concentration of hydrogen ions is nearly the same as the concentration of the acid sollution.

`ph = - log(0.000015) = 4.8239...`

We can round that up to 4.8, meaning we have our answer, 0.000015 M.