Calculate the grammes of oxygen which would involved on heating 5g of potassium trioxochlorate(v)

Answer 1

2KClO3 ==> 2KCl + 3O2
mols KClO3 = g/molar mass = ?
Convert mols KClO3 to mols O2 using the coefficients in the balanced equation.
Now convert mols O2 to grams. g = mols O2 x molar mass O2