Which of the following statements is FALSE regarding water and its properties of life? Water has higher density in liquid form rather than solid form. The bonds within water are made of hydrogen bonds. Within water molecule, electrons spend more time near Oxygen rather than hydrogen. Properties of water such as cohesion and surface tension are due to hydrogen bonds.
The Correct Answer and Explanation is:
The false statement is:
The bonds within water are made of hydrogen bonds.
Water (H₂O) is a unique molecule with several remarkable properties that make it essential for life. Understanding its chemical structure helps clarify these properties. A water molecule consists of two hydrogen atoms covalently bonded to one oxygen atom. In a covalent bond, atoms share electrons. However, because oxygen is more electronegative than hydrogen, it pulls the shared electrons closer to itself, creating a polar molecule. This polarity means the oxygen end of the molecule has a partial negative charge, while the hydrogen ends have partial positive charges.
The polarity of water allows individual water molecules to form hydrogen bonds with each other. A hydrogen bond is a weak interaction between the partially positive hydrogen atom of one water molecule and the partially negative oxygen atom of another. These hydrogen bonds are not the bonds within the water molecule but rather between different water molecules. This distinction is crucial because the statement incorrectly identifies the nature of the bonds inside the molecule. The bonds within a water molecule are covalent, not hydrogen bonds.
Water exhibits several life-supporting properties due to hydrogen bonding. Cohesion, the tendency of water molecules to stick to each other, results in surface tension, allowing small organisms to walk on water surfaces. Adhesion, another property, enables water to climb against gravity in plant vessels. Furthermore, hydrogen bonding explains why water has a high specific heat, helping organisms maintain stable internal temperatures.
One of water’s most unusual features is that its solid form, ice, is less dense than its liquid form. This occurs because hydrogen bonds arrange water molecules in a crystalline structure that occupies more space than when the molecules are in the liquid state, allowing ice to float on water—a critical feature for aquatic life in cold climates.
