Write the formula for the compound

Question

Write the formula for the compound cobalt(IV) sulfate?

Answer 1

As an ionic compound, we need to balance the charges to make the formula. The cobalt is +4 (that's what Cobalt(IV) means). so we need to get the right amount of sulfate ions to add up to a -4 in order to balance the charge (the compound is neutrally charged). We look up Sulfate and see it is SO₄^2- so we need a quantity of two of these to get a -4 charge. That means the formula would be Co(SO₄)₂