Urgent Chemistry Help? Please

At STP, 20 grams of oxygen gas is used to burn potassium metal. What is the mass of oxide produced?

Ok so STP is outta the picture because it has no relevence since all I need to do is find mass which is molar mass times moles. But I am stuck since the beginning.

Since it is being burned it is combustion, which produces CO2 and H2O. Problem is where is the carbon and hydrogen in the reactants. They are nonexistent to my understanding, please help.

This is how I understand it

K + O2 ---> CO2 + H2O Please help

There are some basics flaws in what you are doing. If you are burning potassium, how can you get carbon as a product? Have you learned the Conservation of Mater. It cannot be created or destroyed.

CO2 and water form when you are burning a hydrocarbon, not K

The equation is 4K + O2 >>> 2K2O

Convert the 20 grams of O2 to moles. Multiply by 2 to get moles of the oxide. Multiply by the mol. mass to get grams

ok well just because something is burned doesnt make it a combustion therefore your products are wrong.

so you do 20g O2 / 32(MM o2) times (Coefficient of oxide divided by coefficient of o2)
The coefficients is what you get when you balance the equation correctly