in equation al+hcl=alcl+h2why alcl is not alcl3???

Al + HCl ---------> AlCl + H2
We get AlCl and not the AlCl₃ this can be understand by balancing the above equation,
1). Now balancing the equation we see 2 atoms of hydrogen in product side so multiplying the HCl with 2 on reactant side so that it gets balanced on both sides we get,
Al + 2HCl ------------> AlCl + H₂
2) Observe Cl on reactant side,thus multiply AlCl with 2 so as to balance Cl on both the sides,
Al + 2HCl ------------> 2AlCl + H₂
3).Now look at the no. of Al on product side these are 2 so balancing it, multiply it with 2 on reactant side we get,
2Al + 2HCl -------------> 2AlCl + H₂
Thus we get AlCl and not AlCl₃