Reactant because 2KCl is adding to 3O2 , the numbers in front are coefficients and the numbers on bottom are subscripts , whenever you see an equation adding with another it is a reactant and when the arrow shows , the number that is pointing from it like 2KCIO3 is a product .
Sometimes the reaction is switched and product arrow is at the end so whichever the arrow points too so the product
Answer: Reactant
