Question

What is the pH of each of the following aqueous solutions? (a) 0.036 M HCl WebAssign will check your answer for the correct number of significant figures. 1.44 Correct: Your answer is correct. (b) 0.17 M KOH WebAssign will check your answer for the correct number of significant figures. 13.23 Correct: Your answer is correct. (c) 0.19 M Ba(OH)2

Answer 1

Step-by-step explanation:

(a) 0.036 M HCl

[HCl] = 0.036 M

As HCl is a strong acid, it will completely dissociate and produce H+ ions.

[ H+] = M

pH = −log [ H+]

pH = −log[0.036]

pH = −(−1.444)

pH = 1.44

(b) 0.17 M KOH

pH + pOH = 14

pH = −log10[H+], and pOH = 14−pH

pH = 14 − pOH

pH = 14 − (−log10(0.17))

pH = 14 − (0.77) = 13.23

(c) 0.19 M Ba(OH)2

[H+] [OH−] = 1.0×10−14M

[OH−] = 2 * 0.19 = 0.38M

[H+] = 2.63 ×10−14M

pH = −log10([H+])

pH = −log10(2.63 ×10−14) = 13.58.