Hello!
The answer is: Al2S3(s)+6H2O(l)→2Al(OH)3(s)+3H2S(g)
Why?
Balancing equations is the process where we look for an equal number atoms for each element on both sides of a chemical reaction (reactants and products) in order to satisfy the Law of Conservation of Mass, which states that the mass is equal before and after the reaction.
So, we have to check the number of atoms for both sides of the reaction:
Reactants:
Al=2 atoms
S= 3 atoms
H= 2 atoms
O = 1 atom
Products:
Al = 2 atoms
O = 6 atoms
H = 6 + 6 atoms = 12 atoms
S= 3 atoms
So, we can see that there is a difference between the number of atoms of Hydrogen, there are 2 atoms for the reactants and 12 for the products, for the Oxygen we can see that there is just 1 atom for the reactants and 6 for the products.
To adjust the number of atoms of Hydrogen and Oxygen, we just need to multiply the compound by 6 (H2O)
Al2S3(s)+6H2O(l)→2Al(OH)3(s)+3H2S(g)
Therefore, we have the same number of atoms for each element on both sides of the chemical reaction.
Have a nice day!