My teacher says the correct way to predict/balance the equation AL+HCL yields H+AlCl3 is to balance it like this: 2Al+6HCl yields 3H2+2AlCl3. I don't get why there is a two in front of the AlCl3. Could you guide me through the logic of this please?

Surely.

You have 2 Al on the left; therefore, there must be a 2 for 2AlCl3 to keep the Al atoms the same on both sides.
Second reason:
There are 6 Cl atoms on the left (from 6HCl) and there must be 6 Cl atoms on the right. A 2 coefficient for 2AlCl3 gives 2 Al and 6 Cl in one swell foop.

I'm still a little unsure in front of the first Al why there's a two. Could you explain?

Since you have the cooefficient of 6 before HCl, you must have 6 Cl atoms on the other side as well.

AlCl3 already has 3 Cl atoms so if you put a 2 as the coefficient that gives you 6 (2 x 3 =6).

You have balanced the Cl atoms but now you have unbalanced Al atoms. If you put a 2 in front of the first Al then it balances.

post if you still don't understand

To balance the chemical equation AL + HCL yields H+AlCl3, we need to make sure that the number of atoms of each element is the same on both sides of the equation.

First, let's break down the equation into its individual components:
Aluminum (Al) + Hydrochloric acid (HCl) yields Hydrogen (H) + Aluminum chloride (AlCl3)

Now, let's count the number of atoms on each side of the equation:

On the left side:
- We have 1 Al atom
- We have 1 Cl atom (from HCl)

On the right side:
- We have 1 H atom (from H+ in HCl)
- We have 3 Cl atoms (from AlCl3)

As you can see, the number of Cl atoms does not match on both sides. To balance this, we can multiply the number of AlCl3 molecules by 2, resulting in 2AlCl3. This will give us 2 Al atoms and 6 Cl atoms on the right side.

So, the balanced equation becomes:
2Al + 6HCl yields 3H2 + 2AlCl3

By doing this, we ensure that the number of atoms of each element is the same on both sides of the equation, following the law of conservation of mass.