Water

Physical and Chemical Properties of Water: Water is transparent, tasteless, odorless, and nearly colorless. Chemical formula H2O indicates two hydrogen atoms connected to one oxygen atom. Water covers about 71% of Earth’s surface. Water exists in solid, liquid, and gaseous states on Earth. Water plays a vital role in the global economy, agriculture, and food supply. Water is used as a solvent in various industrial processes and cooking. Water has specific thermal properties like boiling point, vapor pressure, thermal conductivity, refractive index, and viscosity. Water has a hexagonal crystal structure and a bent molecular shape. Water has a dipole moment and acidity/basicity properties. Water is a polar inorganic compound and the universal solvent. States and Properties of Water: Water molecule consists of two hydrogen atoms and one oxygen atom. Water has three common states: solid (ice), liquid, and gas (water vapor). Water becomes less dense as it freezes. Ice has a density of 917kg/m³. Water boils at 100°C and freezes at 0°C at 1 atm pressure. Water can remain liquid at high temperatures in specific conditions. Water is a diamagnetic material and exhibits phase transitions like melting and boiling. Pressure affects the melting and boiling points of water. Water has triple and critical points, including a supercritical fluid phase. Chemical Properties and Solubility of Water: Water is poorly soluble in haloalkanes, aliphatic, and aromatic hydrocarbons. Water has improved solubility in carboxylates, alcohols, ketones, and amines. Water is miscible with substances like methanol, ethanol, and acetone. Water is partially miscible with diethyl ether, methyl ethyl ketone, and ethyl acetate. Water is a good polar solvent due to hydrogen bonding and molecular polarity. Water Cycle and Resources: Water cycle involves processes like evaporation, transpiration, precipitation, and runoff. Water resources include stocks like glaciers, groundwater, and flows like rivers and lakes. Aquifers can store water for thousands of years, while lake volumes fluctuate seasonally. Unsustainable groundwater withdrawals for irrigation lead to depletion. Global freshwater distribution: glaciers (69%), groundwater (30%), other sources (1%). Importance of Water in Life and Society: Water is essential for all known forms of life, metabolic processes, and replication. Water is crucial for anabolism, catabolism, photosynthesis, respiration, and enzyme function. Water supports diverse aquatic life forms and is central to ecosystems. Access to safe drinking water is vital for human health and development. Water scarcity, sanitation issues, and competition for water resources pose global challenges.