Answer : A complete balanced chemical equation is the one where every element has the number equivalent on both the sides of the reaction i.e. on reactant and product side.
Here, [tex]BCl_{3} + H_{2}O ---> H_{3}BO_{3} + HCl[/tex]
Now, we have to check for the same number of elements on either side of the reaction
By looking at the reaction B is only 1 so it is balanced;
Cl is 3 on reactant side but 1 on product side...(needs to be balanced)
H is 2 on reactant side and 4 on product side...(needs to be balanced)
O is 1 on reactant side and 3 on product side...(needs to be balanced)
So, multiplying with 3 and rearranging the equation with their co-efficients we get;
[tex]BCl_{3} + 3H_{2}O ---> H_{3}BO_{3} + 3HCl[/tex]
