What is the molarity of 555 l of a ba (oh) 2 solution if the ph is 10.20? 1. 2.26 * 10-5 m 2. 6.31 * 10-11 m 3. 5.15 * 10-7 m 4. 3.15 * 10-11 m 5. 3.14 * 10-4 m 6. 1.58 * 10-4 m 7. 7.92 * 10-5 m 8. 4.40 * 10-2 m?

First, you need to get POH from the value of PH:

when POH = 14 - PH

= 14 - 10.2

= 3.8

then we are going to get the value of [OH] from the POH value:

POH = - ㏒[OH-]

3.8 = - ㏒ [OH-]

∴[OH-] = 1.58 x 10^-4

then, we will get the moles of ba (OH) 2 = (1.58 x 10^-4) / 2

= 0.0000792 moles

∴ the molarity of Ba (OH) 2 = 7.92 x 10^-5