% of chlorine in Calcium Hypochlorite

[Daiceman]

I was wondering how you get the % of availible chlorine in a substance, i've found places that say the % is 65 for calcium hypochlorite, how did they get this number? If I use its atomic weight, it is only about 49.59%. Ca(OCl)2 is the correct formula right?

 

[cub3bead]

The Pennwalt process of producing calcium hypochlorite is capable of yielding a +70% available product but it was reduced to 65% in 1979 to reduce fire hazards.

Regarding the formula, the product is actually calcium hypochlorite dihydrate so you need to account for 2 waters of hydration. There is also 3-5% excess lime content.

Information source: Geo. Clifford White's Handbook ofCchlorination