Question

Water has a very high boiling point and a very high specific heat. Explain the importance of these two characteristics and how they contribute to life on earth

Answer 1

High B.P. of water
Water molecules are held together by hydrogen bonding, which is a very strong intermolecular force. Each water molecule is polar because the oxygen has a partial negative charge, while the hydrogen atoms have a partial positive charge. The partial negative charge of one water molecule exerts a strong attractive force over the partial positive charge of a different water molecule. In order to boil water, the molecules have to be supplied with a sufficient amount of kinetic energy to escape the strong hydrogen bonding between molecules. The temperature must be increased in order to increase the kinetic energy of the molecules. The presence of the hydrogen bonds thus elevates the boiling point of water.

Heat capacity of water
It takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules. In other words, water has a high specific heat capacity, which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius. The amount of heat needed to raise the temperature of 1 g water by 1 °C is has its own name, the calorie.
Because of its high heat capacity, water can minimize changes in temperature. For instance, the specific heat capacity of water is about five times greater than that of sand. The land cools faster than the sea once the sun goes down, and the slow-cooling water can release heat to nearby land during the night. Water is also used by warm-blooded animals to distribute heat through their bodies: it acts similarly to a car’s cooling system, moving heat from warm places to cool places, helping the body keep an even temperature.
These two properties has some very important implications, especially for organisms that live in water. Seas, lakes and rivers maintain a much more constant temperature than air, which means that animals can live in water all year round without having to adapt to large temperature changes. This also means that our body temperature is reasonably difficult to change quickly and hence makes our brain's job of maintaining a constant body temperature much easier.
This is how water contribute to life on earth.