IMG_0386.jpeg

# Properties of Water **4. Properties of water** - Very stable substance - Reacts with alkali metals and alkaline earth metals (s¹ more vigorously than s²) at normal temperatures: ``` 2Na + 2H₂O → 2NaOH + H₂↑ ``` - And with some transition metals at high temperatures (like steam): ``` 3F...

# Properties of Water **4. Properties of water** - Very stable substance - Reacts with alkali metals and alkaline earth metals (s¹ more vigorously than s²) at normal temperatures: ``` 2Na + 2H₂O → 2NaOH + H₂↑ ``` - And with some transition metals at high temperatures (like steam): ``` 3Fe + 4H₂O(g) → Fe₃O₄ (FeO⋅Fe₂O₃) + 4H₂↑ ``` **Acid-base properties of water** - From the pH perspective, it is neutral: ``` 2H₂O ⇌ H₃O⁺ + OH⁻ ``` Oxonium cation + Hydroxide anion - It has amphoteric character: - With acid-forming oxides, it behaves as a base - With base-forming oxides, it behaves as an acid (reaction see with oxides) - As a product, it is formed during neutralization **5. Water as a solvent** - Polar solvent - it has a polar molecule → it dissolves many inorganic substances with polar and ionic bonds (in all states) - these are broken down in water into hydrated ions (surrounded by water molecules = solvation) - We talk about electrolytic dissociation and the resulting solution is an electrolyte ``` H₂O NaCl → Na⁺ + Cl⁻ ``` - If substances with weakly polar or nonpolar bonds (e.g. organic) are dissolved, there is no splitting into ions, but only covering of their molecules by water molecules - solvation (solution is not an electrolyte) **Diagram Description** A diagram shows a cluster of positive and negative ions surrounding a molecule of water. The ions seem to be dissolved in the water.