# Chemistry

posted by
**Krissy** on
.

I was given a question on an assignment and I can't figure it out.

The question is

A student collects 90ml of oxygen gas over water at 25c and a total pressure of 99.3kPa from the decomposition of KClO3.

2KClO3(s)-> 2KCl(s)+ 3O2

a) How many mols of O2 were collected?

b)How many grams of KClO3 was decomposed?

For part a) would I change ml to L and then divide this number by the molar mass of O2 to get my answer?

for part b) I have no idea how to even attempt this any help is greatly appreciated.

on a side not would I change kPa to atm? if so is 99.3kPa*1atm/101kPa = .989 ?

Thank you in advance for any attempts made to help me figure this out.