Question

What is the empirical formula for the product that is formed when `K` and `Cl_2` combine?

Answer 1

`KCl`

Explanation:

When potassium solid (`K`) is mixed with chlorine gas (`Cl_2`) the reaction is the following:

`2K(s)+Cl_2(g)->2KCl(s)`

The empirical formula, which is the same as the formula unit would be: `KCl`.

Note that ionic compounds are always written as their empirical formula.