Question

2 KClO3(s)--> 2 KCl(s) + 3 O2(g)
How many milliliters of O2 will form at STP from 38.8 g KClO3?

Answer 1

Convert 38.8 g KClO3 to moles. moles = grams/molar mass

Using the coefficients in the balanced equation, convert moles KClO3 to moles oxygen.

Convert moles O2 to liters. liters = mols x 22.4 L/mol = ??

Answer 2

so would the problem be set up as:

(38.8 g KClO3) * (1 mol / 122.5 KClO3) * (2 mol KCL / 3 mol O2) * (22400 mL O2 / 1 mol)

or

(38.8 g KClO3) * (1 mol / 122.5 KClO3) * (3 mol O2 / 2 mol KCl) * 22400 mL O2 / 1 mol) ?