Liquids heavier than water include glycerin, milk, sulphuric acid, molasses, methanol, isopropyl alcohol, ethanol, saltwater and corn syrup. Water has a density of 1.0 g/cc at room temperature.
Glycerin has a density of 1.2 g/cc, and light corn syrup has a density of 1.33 g/cc.
Mercury at room temperature is normally in liquid form and is 13.6 times denser than water.
Naturally, water contains salts, minerals and gases. When a large amount of material is dissolved in pure water, it becomes more dense. For instance, saltwater is denser than pure water. Needless to say, ocean water is denser than tap water.
The density of water also varies if the temperature changes. Water that is about 39 F (4 C) is denser than water at 32 F (0 C).