Discuss how hydrogen bonding in water allows water to support life on earth. Include in your answer how hydrogen bonding affects the physical and chemical properties of water

Question

What will be an ideal response?

Answer 1

The hydrogen bonds between water molecules are much weaker than the covalent bonds that hold the hydrogen and oxygen atoms of water molecules together. In essence, weaker hydrogen bonds form between adjacent water molecules, and stronger covalent bonds occur within water molecules. Even though hydrogen bonds are weaker than covalent bonds, they are strong enough to cause water molecules to stick to one another and exhibit cohesion. Water molecules stick not only to other water molecules but also to other polar chemical compounds. In doing so, water molecules can reduce the attraction between ions of opposite charges by as much as 80 times. Because water molecules interact with other water molecules and other polar molecules, water is able to dissolve nearly everything. Almost every other liquid contracts as it approaches its freezing point, but water actually expands as it freezes. Thus water stays at the surface as it starts to freeze, and ice floats—a rare property shared by very few other substances. If water's properties followed the pattern of similar chemical compounds, ice would sink and cause all temperate-zone lakes, ponds, rivers, and even oceans to eventually freeze solid from the bottom up; in this scenario, life on Earth as we know it would not exist. Instead, a floating skin of ice forms at water's surface and acts as an insulating cover to protect the organisms that live in the liquid water below. The chemical properties of water are also essential for sustaining all forms of life. In fact, the primary component of all living organisms is water. The water content of organisms, for instance, ranges from about 65% (humans) to about 90% (most plants) to as much as 95% in jellies. Water is the ideal medium to have within our bodies because it facilitates chemical reactions. Our blood, which serves to transport nutrients and remove wastes within our bodies, is 83% water. The very presence of water on our planet makes life possible, and its remarkable properties make our planet livable.