In the reaction, Al2O3 + __HCl → 3H2O + 2AlCl3, what coefficient should be placed in front of HCl to balance the reaction? 1 2 3 6

6

Al2O3 + 6HCl → 3H2O + 2AlCl3,

Explanation:

The chemical equation given is

Al2O3 + HCl → 3H2O + 2AlCl3,

Balancing the equation requires you to make the number of atoms on the left hand side (reactant) equal to the number of atom on the right hand side (product).

On the left hand side;

Al has 2 atom, oxygen has 3 atom, hydrogen has 1 atom and chlorine has 1 atom.

on the right hand side;

hydrogen is 6 atom, oxygen has 3 atom, Al has 2 atom and chlorine has 6 atoms.

The number of hydrogen atom and chlorine atom is not equal on both sides. To make it equal we add a coefficient of 6 in front of HCl to make the atoms equal on both sides.

Al2O3 + 6HCl → 3H2O + 2AlCl3

Al2O3 + 6HCl gives 3H2O + 2AlCl3

the answer is 6