Answer:
NaClo3 is the reactant here.
Explanation:
In the reaction below:
[tex]H_{2} + O_{2}[/tex] ----------------------> 2[tex]H_{2} O[/tex]
Here [tex]H_{2}[/tex] and [tex]O_{2}[/tex] are reactant, they take part in chemical reaction to form water as a product.