Based on the following word descriptions, write the formula for each of the indicated substances.
(Express your answer as a chemical formula.)
A compound whose molecules each contain six carbon atoms and six chlorine atoms.
Formula:
An aluminum compound in which there are three bromine atoms for each aluminum atom.
Formula:
A compound in which there are two potassium atoms for every sulfur atom.
Formula:
A compound whose molecules each contain two nitrogen atoms and four oxygen atoms.
Formula: