# Chemistry

What is the OH- concentration of a solution whose pH is 12.40?

1. 👍
2. 👎
3. 👁
1. Trinity,

from the pH you can determine the H3O^+ concentration by using ph=-log[H3O^+]. Then you can use Kw=KaxKb to solve for OH- concentration

10^-12.40 = 10^log[h3o^+] =
4.0x10^-13 M = [h3o^+]

Now use 4.0x10^-13[OH^-] = 1.00x10^-14 =

[OH^-]= 2.5X10^-2 M

1. 👍
2. 👎
2. thanks@ Michael

1. 👍
2. 👎
3. pH + pOH = pKw = 14.
You know pH, solve for pOH.
Then pOH = -log(OH^-)
Substitute and solve for OH. You should get a little less than 2 but that's just an estimate.

1. 👍
2. 👎
4. Thanks @ DrBob222

1. 👍
2. 👎
5. I hit the wrong key. The answer should be a little less than 3.

1. 👍
2. 👎
6. If [H3O+] = 1.7 x 10–3 M, what is the pH of the solution?

1. 👍
2. 👎

## Similar Questions

1. ### Chemistry

The titration of 25.0 mL of an unknown concentration H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution (in M)? A) 0.40 M B) 0.10 M C) 0.20 M D) 0.25 M E) 0.36 M The answer is

2. ### AP Chemistry

A given weak acid HZ has a Ka=1.7×10−6. What is the H3O+ concentration of a solution of HZ that has a concentration of 0.78 mol/L? What is the pH of this solution of HZ? What is the percent ionization of HZ in this solution?

3. ### Chemistryyy

a) A standard solution of 0.243 M NaOH was used to determine the concentration of a hydrochloric acid solution. If 46.33 mL of NaOH is needed to neutralize 10.00 mL of the acid, what is the molar concentration of the acid? b) A

4. ### Analytical chemistry

A 25.0-mL solution of 0.0660 M EDTA was added to a 33.0-mL sample containing an unknown concentration of V3 . All V3 present formed a complex, leaving excess EDTA in solution. This solution was back-titrated with a 0.0450 M Ga3

1. ### Chemistry

I have discovered a new chemical compound with the formula A2B. If a saturated solution of A2B has a concentration of 4.35x10-4M. a) What is the concentration of B2- ions? b. What is the concentration of A1+ ions? c. What is the

2. ### chemistry

A is a solution of trioxonitrate(v) acid, HNO3, of unknown concentration. B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution. 25cm3 portions solution B required an average of 24.00cm3 of solution A for

3. ### CHEMISTRY

If the OH ion concentration in an aqueous solution at 25 celsius is 3.4x10^-3 M the the H concentration in moles per liter in the same solution is? answers is 2.9x10^-12 i do the -log and i get 2.46 i don't know that else

4. ### Chemistry

A is a solution of trioxonitrate (v)acid, HNO3 of unknown concentration.B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution. 25 cm3 portion solution B required an average of 24.00cm3 of solution A for

1. ### chemistry

When the glucose solution described in part A is connected to an unknown solution via a semipermeable membrane, the unknown solution level rises. Based on this information, what can be said about these two solutions? a.) The

2. ### Chemistry

The pH of a solution is 1. Which of the following statements are also true for the solution? (Select all that apply.) It will change the color of red litmus to blue. The concentration of hydronium ion is equal to the concentration

3. ### Chemistry

What hydroxide concentration is required to (a) Initiate precipitation of Ag2CrO4 from a solution that is 2.12 x 10^-3 M in Ag+? (b) lower the Al^3+ concentration in the foregoing solution to 1.00 x 10^-9

4. ### CHEMISTRY

A solution of H2SO4(aq) with a molal concentration of 1.94m has a density of 1.119g/mL. What is the molar concentration of this solution? I got an answer of 2.17 M and it is incorrect..please help. My work: So Molar concentration