Question

Aluminum ions form an ionic bond with chromate ions and the resultant formula is Al2(CrO4)3. What is the ion charge for the chromate ion?

Answer 1

2+

2-

3+

3-

Answer 2

Do you know the ion charge of an aluminum ion?

Answer 3

XD I just had to hit refresh on that last question
Well.... There's no negative sign in the problem so I'm guessing it positive

Answer 4

Yeah, metals are the positive ion in an ionic bond. Well, aluminum has a +3 charge in ionic bonds. Since there are 2 aluminum atoms per molecule, the total positive charge is +6.

Since a molecule needs to have 0 net charge, you can figure out the ion charge of one chromate ion. :3

Answer 5

So if you divide +6/2 then you get +3

Answer 6

What. .-. +3 is the charge of one aluminum ion. +6 for the two aluminum ions that make up a molecule of (Al)2(CrO4)3

Answer 7

The total charge of a molecule has to be 0, and there are 3 chromate ions that make up this molecule.
+6 + 3x = 0, where 'x' is the charge of the chromate
3x = -6
x = -2

A chromate ion has a charge of -2. :3