# Homework Help: Mass-Volume stoichiometry

1. Oct 8, 2012

### Mackydoodle

1. The problem statement, all variables and given/known data
How many millilitres of oxygen gas are released from heating 5.00 grams of calcium chlorate?

2. Relevant equations

Ca(ClO3)2→CaCl2+3O2

Ca(ClO3)2 =207.7g
CaCl2=110.98g
O2=22.4 g/L
Mole ratio= 3mol O2/1mol Ca(Clo3)2

3. The attempt at a solution
This is what I have but it is not coming out right and I just cant figure out where im going wrong. I am having trouble with these kinds of problems.

(207.7 g/ 1 mol Ca(Clo3)2) X (1mol Ca(Clo3)2/3 mol O2) X (22.4 L O2/ 1 mol O2)= 1550.8
(this cant be right the answer is supposed to be 1620)

Last edited: Oct 8, 2012
2. Oct 8, 2012

### AGNuke

Moles of Calcium Chlorate (Given Mass / Molar Mass)* Moles of dioxygen per mole of Calcium Chlorate (3) * Volume of 1 mole dioxygen (22.4 L / mol).

The answer is approximately 1617. (1620 if you approximately calculate it manually)

3. Oct 8, 2012

### Mackydoodle

I now see where I went wrong!! thank you :)