Chemical Properties of Water
1. Amphoteric nature: Water can act as both acid and base, which means that it is amphoteric in nature.
2. Redox reactions: Electropositive elements reduce water to hydrogen molecule. Thus, water is a great source of hydrogen. Let us see an example in this case: During the process of photosynthesis, water is oxidized to O2. As water can be oxidized and reduced, it is very useful in redox reactions.
3. Hydrolysis reaction: Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.
4. Self-Ionisation (Auto-Protolysis of Water): The ionisation of water takes place in the process of autoprotolysis of water which means in order to form a hydroxide ion OH−,H2O deprotonates (proton removal).
Physical Properties of Water
1. Appearance: Water is a colorless, odorless, and tasteless liquid in its natural state. The crystal structure of water is hexagonal.
2. Boiling and Melting points of Water: The boiling point is defined as the temperature at which the vapor pressure of the liquid is equal to the pressure surrounding the liquid, and thus the liquid changes to vapor and the melting point is the temperature at which the substance changes state from liquid to solid. It is known to us that the boiling point of water is approximately 100°C and its melting point is 0°C.
3. Specific Heat Capacity: Water has a high specific heat capacity of 4.2 joules per gram at 25°C. This is due to the extensive hydrogen bonding between the water molecules.
4. Refractive Index of Water: In simpler words, the refractive index is the number that describes how fast light reaches the material. The refractive index of water is 1.333 at 20°C.
Properties
Value
Chemical Formula
H2O
Odour
None
Molar mass
18.01528(33) g/mol
Boiling point
99.98 °C (211.96 °F; 373.13 K)
Melting point
0.00 °C (32.00 °F; 273.15 K)
Solubility
Poorly soluble in aliphatic and aromatic hydrocarbons, and Ethers. Improved solubility in amines, ketones, alcohols, carboxylates. Miscible with acetonitrile, dimethyl sulfoxide, dimethoxyethane, dimethylformamide, acetaldehyde, sulfonates, tetrahydrofuran, 1,4-dioxane, glycerol, acetone, isopropanol, propanol, ethanol, methanol. Partially miscible with Bromine, Ethyl Acetate, Diethyl ether, Dichloromethane.
Structure
Value
Crystal structure
Hexagonal
Molecular shape
Bent
Dipole moment
1.8546 D