How many times heavier is chlorine gas compared to water?

Chlorine gas is approximately 1.5 times heavier than water. This is determined by examining the molecular weights of both substances. The molecular weight of chlorine (Cl) is about 35.45 g/mol, while that of water (H₂O) is approximately 18 g/mol.

When comparing the densities of these substances at standard temperature and pressure, chlorine gas, being a diatomic molecule, has a lower density compared to water in its liquid state. However, when calculating how many times heavier chlorine gas is than water, we find that the ratio of the density of chlorine gas to that of water gives us the factor of about 1.5. This understanding is essential, especially in wastewater treatment processes where chlorine is commonly used for disinfection, necessitating knowledge of its properties in comparison to water.