Have I balanced this right

Al2Se3 + 6 H2O ==> 2 Al(OH)3 + 3 H2Se

Let me give you a hint on these, write water as HOH, and it balances faster. Treat the OH as a group.

Al2Se3 + 6 H(OH) ==> 2 Al(OH)3 + 3 H2Se

Yes, it is balanced: see the six H on each side, and the six OH on each side..

To check if the given chemical equation is balanced correctly, we need to examine the number of atoms of each element on both sides of the equation.

Here's how you can balance the equation:

Al2Se3 + 6 H2O → 2 Al(OH)3 + 3 H2Se

For the atoms Al (aluminum), Se (selenium), and H (hydrogen), we have:
On the left side, we have 2 Al atoms, 3 Se atoms, and 12 H atoms.
On the right side, we have 2 Al atoms, 3 Se atoms, and 12 H atoms.

This indicates that the equation is balanced in terms of Al and Se.

However, when we examine the number of oxygen (O) atoms, we find a discrepancy:
On the left side, we have 6 O atoms from the 6 water molecules.
On the right side, we have only 6 O atoms from the 3 hydroxide (OH) groups in 2 Al(OH)3.

To balance the oxygen (O) atoms, we need to add 6 more OH groups to the right side of the equation, resulting in 12 O atoms on both sides.

The balanced equation will be:

Al2Se3 + 6 H2O → 2 Al(OH)3 + 3 H2Se

So, no, the given equation is not balanced correctly. We need to add 6 more OH groups on the right side to balance the number of oxygen atoms.