Water is unique in almost all its physical and chemical properties. The reason for the peculiar behavior of water lies in its molecular structure: Water molecules consist of two hydrogen and one oxygen atom arranged asymmetrically, producing an electrical dipole. A positively charged hydrogen atom is attracted to a negatively charged oxygen atom forming a powerful hydrogen bond between neighboring water molecules. Thus water molecules have a strong affinity toward each other and to other molecules. This accounts for water's strange 'heat' properties and strong powers to dissolve.
In consideration of the light molecular weight of water it has remarkably high melting and boiling points. Phase transitions from solid to liquid and to vapor require the addition of large quantities of heat (latent heat). The heat capacity of water is also very high: its takes a lot of heat to warm water. Conversely as water cools or moves to a lower phase, lots of heat must be removed. Latent heat of water acts to keep atmospheric temperatures within a relative narrow range. Comparison of seasonal swings of air temperature at points far from the modifying effects of the ocean, e.g. in the center of Asia (over 50°C) with air temperature changes over the mid-Pacific (less than 10°C) is an example of the power of water to regulate air temperature.
In this wetlab, we'll be determining the specific heat capacity of freshwater and the latent heat of vaporization. We do this by providing heat at a known rate and measuring the temperature response of a measured mass of water. We begin with cold water and gradually warm that water to the boiling point.