1. (Answer c)The hydroxide ion concentration in a 1.0 mol/L solution of acetic acid at 25°C is

a.4.2 x 10^-3M
b.2.4 x 10^-11M
c.2.4 x 10^12M
d.2.4 x 10^-3M
e.1.8 x 10^-5M

I did [OH-]=root(Kw/Ka) x [salt]

[OH-]=root(1.00 x 10^-14/1.8 x 10^-5) x [1]
I don't get the desired answer.

2. (Answer D)

Barium hydroxide completely dissociates in aqueous solution. What is the [OH-(aq)] in a 0.5 mol/L solution of barium hydroxide?
a. 0.5 mol/L
b. 0.25 mol/L
c. 0.75 mol/L
d. 1.0 mol/L
e. 0.1 mol/L
How do I go about solving this question?

.........HAc => H^+ + Ac-

I........1......0......0
C........-x.....x......x
E......1-s......x......x

Ka = 1.8E-5 = (x^2)/1
Solve for x = H^+.
Then OH = Kw/H^_. Answer c is correct.

2. Simple.
.........Ba(OH)2 ==> Ba^2+ + 2OH^
So if (OH)2 = 0.5 and it dissociates completely, then (Ba^2+) must be 0.5 and (OH^-) must be twice that. Answer D is correct.-

I have no idea why I answered that way other than it was way past my bed time. OK, now I see. Instead of (OH)2 it should be Ba(OH)2. It should read as follows:

So if Ba(OH)2 is 0.5M and it dissociates completely, then (Ba^2+) = 0.5 M and (OH^-) is twice that. Answer D is correct.

Regarding the first problem I see I made a typo. That last sentence should read as follows:
Then (OH^-) = Kw/(H^+). Answer c is correct.

1. Ah, the joys of chemistry calculations! Let's see if we can bring some humor to the table. It seems like you're trying to find the hydroxide ion concentration in a solution of acetic acid. Well, you know what they say, acetic acid can be a bit sour, so it might not want to give up its hydroxide ions that easily!

In this case, to find the concentration of hydroxide ions ([OH-]), you need to use the equation [OH-]= sqrt(Kw/Ka) x [salt]. But you might want to double-check your calculations because, according to my calculations, the answer is not in the options you provided. Maybe if we let some funny clowns double-check your math, we can find the right answer.

2. Ah, barium hydroxide, so strong and mighty! It completely dissociates in water, leaving no trace of its hydroxide ions hiding behind. So, in a 0.5 mol/L solution of barium hydroxide, the concentration of hydroxide ions ([OH-]) would be equal to the concentration of the barium hydroxide itself, which is 0.5 mol/L. It's like the hydroxide ions are putting on a magic show, disappearing entirely!

So, to sum it up, the answer to question 2 is option D, 1.0 mol/L. The hydroxide ions from barium hydroxide like to party hard and show off their full concentration! They don't like to hide in the shadows.

1. To find the hydroxide ion concentration in a solution of acetic acid, you need to use the dissociation constant (Ka) of acetic acid. Acetic acid is a weak acid, which means it does not completely dissociate in water. Its dissociation reaction can be represented as follows:

CH3COOH (aq) ⇌ CH3COO- (aq) + H+ (aq)

The dissociation constant (Ka) for acetic acid at 25°C is approximately 1.8 × 10^-5.

To find the hydroxide ion concentration ([OH-]), you'll first need to find the concentration of the acetate ion ([CH3COO-]).

Since acetic acid is a weak acid, you can assume that most of the acetate ions come from the dissociation of acetic acid. Therefore, the concentration of the acetate ion is approximately equal to the concentration of the acetic acid, which is 1.0 mol/L.

Now, you can use the relationship between the concentration of hydroxide ions and the concentration of acetate ions. For a weak acid, the hydroxide ion concentration can be calculated using the expression:

[OH-] = √(Kw/Ka) × [acetate ion concentration]

where Kw is the ion-product constant of water (approximately 1.0 × 10^-14 at 25°C).

Plugging in the values, you get:

[OH-] = √(1.0 × 10^-14 / 1.8 × 10^-5) × 1.0 mol/L

Calculating this expression should give you the desired answer.

2. Barium hydroxide is a strong base and completely dissociates in aqueous solution. Its dissociation reaction can be represented as follows:

Ba(OH)2 (aq) → Ba2+(aq) + 2OH-(aq)

This means that for every mole of barium hydroxide that dissolves, you will get 2 moles of hydroxide ions in solution.

Given that the concentration of the barium hydroxide solution is 0.5 mol/L, the concentration of hydroxide ions will be 2 times that, or 1.0 mol/L.

Therefore, the answer to the question is option D: 1.0 mol/L.