What mass of potassium hypochlorite (fw-90.6 g/mol) must be added to 4.50 x 10 ml of water to give a solution with ph 10.20? [ka(hcio) 4.0 x 10-8] 0.032g ? 2.4 g 04.1 g 9.1 g 20. g

Answer : The mass of potassium hypochlorite is, 4.1 grams.

Explanation : Given,

pH = 10.20

Volume of water =

The decomposition of KClO  will be :

Now the further reaction with water to give,

First we have to calculate the pOH.

Now we have to calculate the concentration.

Now we have to calculate the base dissociation constant.

Formula used :

Now put all the given values in this formula, we get :

Now we have to calculate the concentration of .

The equilibrium constant expression of the reaction  is:

As we know that,

Now we have to calculate the moles of .

As we know that, the number of moles of are equal to the number of moles of KClO.

So, the number of moles of KClO = 0.0449 mole

Now we have to calculate the mass of KClO.

Therefore, the mass of potassium hypochlorite is, 4.1 grams.