Part A What is the H+ concentration for an aqueous solution with pOH = 2.89 at 2

ID: 946956 • Letter: P

Question

Part A

What is the H+ concentration for an aqueous solution with pOH = 2.89 at 25 ?C?

Express your answer to two significant figures and include the appropriate units.

[H+] =

Part B

Arrange the following aqueous solutions, all at 25 ?C, in order of decreasing acidity.

Rank from most acidic to most basic. To rank items as equivalent, overlap them.

Part C

At a certain temperature, the pH of a neutral solution is 7.88. What is the value of Kw at that temperature?

Express your answer numerically using two significant figures.

Kw =

Part A : pOH = 2.89, therefore pH = 14 - pOH = 14 - 2.89 = 11.11

now pH = - log[H+] = 11.11

therefore [H+] = 10-11.11 = 7.8 x 10-12 M

Part B: 0.0023 M HCl has pH = - log (0.0023) = 2.64

0.0018 M KOH has pOH = - log(0.0018) = 2.74

therefore pH = 14 - 2.74 = 11.26

Thesolution with pOH 8.55 has pH = 14 - 8.55 = 5.45

therefore the acidity order is 0.0023 M HCl > pH 5.45 = pOH 8.55 > 0.0018 M KOH

Part C: pH = 7.88, therefore [H+] = 10-7.88, and as the solution is neutral the [OH-] = [H+] = 10-7.88

Hence Kw = [H+][OH-] = 10-7.88 x 10-7.88 = 10-15.76 = 1.7 x 10-16.