Potassium chlorate >>> potassium chloride + oxygen gas

Look up the formula for each of the components. I'll give you a hint, Oxygen gas is "O2". Write the equation using chemical symbols, then balance the equation.

What happens when sodium hydroxide reacts with water

taddele, would you please start another thread.

FYI, sodium reacts violently with water, and sometimes catches fire, with a yellow flame. If you want more details, start another thread.

what happens when sodium hydroxide reacts with water

Sodium hydroxide simply dissolves in water. It doesn't react with water. When it dissolves the solution will become warm -- even hot -- as the sodium hydroxide gives off the "heat of solution". It has an affinity for water.

Commenting on what the previous poster said, sodium hydroxide is not sodium. Sodium does react violently with water to form hydrogen and sodium hydroxide.

I agree that this should be put in a separate thread.

Oh, sorry, a big mistake of mine. I didn't read it fully and missed the hydroxide. :o