Zyrtec, or cetirizine, has a molecular compound of 21 carbon atoms, 25 hydrogen atoms, 1 chlorine atom, 2 nitrogen atoms, and 3 oxygen atoms. In everyday use cetirizine is used for allergies. It is used to help with the effects of an allergic reaction. It helps with itchy eyes, running nose, and sneezing. It also treats hay fever, angioedema, and hives. Onto the properties of cetirizine. It has a boiling point of 1008 degrees F and a density of 1.2±0.1 g/cm cubed. Zyrtec has a melting point of 110-115 degrees celsius. It has a solubility of 101mg/L and a pKa of 3.6. Zyrtec has a molecular weight of 388.9 g/mol.