## homework 6A.23

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BAlvarado_1L
Posts: 49
Joined: Thu Jul 25, 2019 12:16 am

### homework 6A.23

How are we supposed to find the concentrations of Ba2+, OH−, and H3O+ if we aren't given the Ka or pH?

CynthiaLy4F
Posts: 103
Joined: Sat Jul 20, 2019 12:16 am

### Re: homework 6A.23

For this problem, since it gives you the number of grams of Ba(OH)2, you would convert that into moles and divide it by the given volume of the solution to get the concentration of [Ba2+]. For the concentration of [OH-], you would multiply the concentration of [Ba2+] by 2 because the are 2 moles of OH- for every one mole of Ba(OH)2. Once you find the concentration of [OH-], use Kw to find [H3O+].

Ariel Davydov 1C
Posts: 110
Joined: Thu Jul 11, 2019 12:16 am
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### Re: homework 6A.23

Since Ba(OH)2 is a strong base, it will dissociate almost entirely. Thus, if given the mass of Ba(OH)2 in this particular problem, you can calculate its molarity, set up a balanced equation of Ba(OH)2 dissociating, and use the ratios to find the concentrations of Ba2+ and OH-. From here, you can calculate the Kb value and use Kw to find the Ka. You can also use the OH- concentration to find the pOH, pH, and H3O+ concentration. Hope this helps!

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