INORGANIC CHEM - PERIOD 3

• 2Na + 2H2O -> 2NaOH + H2 • floats • moves around • fizzes • melts • yellow flame • white solid

• steam: Mg + H2O -> MgO + H2 • water: Mg + 2H2O -> Mg(OH)2 + H2 • bright white flame (steam) • white solid (steam) • reacts very slowly with water

• Cl2 + H2O ⇌ HCl + HOCl • dissolves giving very pale green solution

• 4Na + O2 -> 2Na2O • yellow flame • white solid

• 2Mg + O2 -> 2MgO • bright white flame • white solid

• 4Al + 3O2 -> 2Al2O3 • hard for foil to burn • powder burns more easily • white flame • white solid

• Si + O2 -> SiO2 • powder will burn • white flame • white solid

• P4 + 5O2 -> P4O10 • ignites very easily • bright white flame • white smoke

• S + O2 -> SO2 • blue flame • choking toxic gas

• Na2O: ionic • MgO: ionic • Al2O3: ionic with some covalent character • SiO2: giant covalent • P4O10: simple covalent • SO2: simple covalent

• structure: ionic • with water: dissolves and reacts to form a solution Na2O + H2O -> 2NaOH(aq) forms Na^+ and OH^- ions • pH: 14 • with acids: Na2O + 2H^+ -> 2Na^+ + H2O • with alkalis: no reaction • nature: basic

• structure: ionic (higher melting point than Na2O due to Mg^2+) • with water: slightly soluble, reacts slowly MgO + H2O -> Mg(OH)2(aq) • pH: 10 • with acids: MgO + 2H^+ -> Mg^2+ + H2O • with alkalis: no reaction • nature: basic

• structure: ionic with some covalent character (polarising Al^3+) • with water: insoluble (very high lattice enthalpy) • with acids: Al2O3 + 6H^+ -> 2Al^3+ + 3H2O • with alkalis: Al2O3 + 2OH^- + 3H2O -> 2Al(OH)4^- • nature: amphoteric

• structure: giant covalent • with water: insoluble (strong covalent lattice) • with acids: no reaction • with alkalis: SiO2 + 2OH^- -> SiO3^2- + H2O (requires hot, concentrated NaOH) • nature: acidic

• structure: simple molecular • with water: reacts violently P4O10 + 6H2O -> 4H3PO4 releases H^+ ions • pH: 0 • with acids: no reaction • with alkalis: P4O10 + 12OH^- -> 4PO4^3- + 6H2O • nature: acidic

• structure: simple molecular • with water: dissolves to form solution SO2 + H2O -> H2SO3 releases H^+ ions • pH: 3 • with acids: no reaction • with alkalis: SO2 + 2OH^- -> SO3^2- + H2O • nature: acidic

• structure: simple molecular • with water: reacts violently SO3 + H2O -> H2SO4 releases H^+ ions • pH: 0 • with acids: no reaction • with alkalis: SO3 + 2OH^- -> SO4^2- + H2O • nature: acidic