How can I balance the equation ##Zn + HCl -> ZnCl_2 + H_2##?

##Zn +2HCl -> ZnCl_2 + H_2 ##
The method I find it useful when it comes to balancing a chemical equation is to draw a chart corresponding to the number of moles: (Split compounds into one unit of its own but, for polyatomic count them as one whole unit)
Unbalanced chemical equation: Zn + HCl = ZnCl2 + H2Reactant side:
Zn= 1
H=1 X 2 =2 moles of hydrogen
Cl=1 X 2 = 2 moles of
Product side:
Zn=1
H=2
Cl=2
The reason why you need to balance a chemical equation because energy is conserved throughout the chemical process.
Balanced chemical equation:
Zn + 2HCl = ZnCl2 + H2
There are two hydrogens and two chlorines on the left and right sides.