how much oxygen gas wil be produce from the decomosition of 50 grams of pottasium chlorate

3 answers

You need to watch your typing.
2KClO3 ==> 2KCl + 3O2

mols KClO3 = grams/molar mass = ?
Using the coefficients in the balanced equation convert mols KClO3 to mols O2
What do you mean by "How much"? If you want grams, that is grams = mols O2 x molar mass O2.
If you want volume, that is L = mols O2 x 22.4 L/mol = ?L

.306 moles of O2

Mol's of KClO3=122.6 grams