QUESTION: Which of the following is not a property of water?
A It becomes denser when it freezes.
B It dissolves molecules in the air.
C It absorbs heat when the hydrogen bonds break
D It forms hydrogen bonds with other water molecules to create surface tension.
ANSWER: It becomes denser when it freezes.
| Properties of water | Description |
| Chemical formula of water | H2O |
| Molecular structure | Water consists of two hydrogen atoms covalently bonded to one oxygen atom |
| Polar nature | Water consists of oxygen having a partial negative charge on it and hydrogen having a partial positive charge, making it a polar molecule. |
| Universal solvent | Water is also known as the universal solvent. Due to its polar nature, it has the ability to dissolve large amount of substances in it. |
| High heat of capacity | Water has a high specific heat capacity, thus it can absorb and store a significant amount of heat in it without a significant change in temperature. |
| High heat of vaporization | Water requires a considerable amount of heat to convert it from liquid to vapor state. |
| Property of cohesion and adhesion | Water molecules exhibit cohesion and adhesion nature leading to properties like surface tension, capillary action and the ability to transport water in plants. |
| Freezing Behavior
| Water’s density is highest at around 4°C.When it freezes at 0°C; molecules of water arrange themselves in to a hexagonal structure, creating solid ice. Density of ice is about 9% lower than the density of liquid water due to which ice floats on the water. |
| Surface Tension | Water’s cohesive forces at the surface create surface tension. This property allows some insects to walk on water and also contributes to capillary action in plants. |
| pH | Pure water has a pH 7, making it neutral on the pH scale. Yet water is an amphoteric substance as it can act as an acid as well as a base depending upon the nature of the substances it interacts with. |
| States of water | Water can exist in all three states of matter at room temperature such as solid, liquid and gas. |
| Hydrogen Bonding | Water molecules exhibit hydrogen bonding with each other, leading to high boiling and melting points. |
| Transparent nature | Water is transparent to visible light, allowing light to penetrate and enabling aquatic ecosystems to support photosynthesis. |
| Electrical Conductance | Water can conduct electricity to some extent due to the dissociation of a small portion of water molecules into ions (H+ and OH-). |