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

The molar mass of a substance is defined as the mass of 1 mol of that substance, expressed in grams per mole, and is equal to the mass of 6.022 × 10 23 atoms, molecules, or formula units of that substance.