Groups

View mindmap
  • Groups
    • Group 2
      • Reactions
        • They react with water to produce metal hydroxides and hydrogen
          • E.g. Ca(s) + 2H2O(l) --> Ca(OH)2(aq) +H2(g)
        • Burn in oxygen to form solid white oxides
          • E.g. 2Ca(s) +O2)g) --> 2CaO(s)
        • Decompose to form G2 oxide and CO2(g)
          • E.g. CaCO3(s) --> CaO(s) +CO2(g)
      • Trends
        • Solubility
          • Compounds of G2 metals that contain singly charged -ve ions (e.g. OH-) increase in solubility down the group
          • Compounds of G2 metals that contain doubly charged -ve ions (e.g. (CO3)2- and (SO4)2-) decrease in solubility down the group
        • Reactivity
          • Get more reactive down the group because outermost electrons are further from the nucleus so more easily lost
        • Thermal stability
          • Increases down G2
            • Large cations cause less distortion of the carbonate anion since they have a lower charge density so are more stable
    • Group 7
      • Trends
        • Reactivity
          • Less reactive down the group since outer-shell electrons further from nucleus so more shielding and less attraction to positive nucleus so harder to attract an electron
        • Volatility
          • Get less volatile down G7 since RAM increases so number of IDIDs increases
        • Solubility
          • Since they're covalent and non-polar they have low solubility in water but will dissolve in organic solvents e.g. hexane
      • Halogen-Halides
        • If Br2 is formed: yellow/orange in (aq) and orange/red in hexane
        • If I2 is formed: brown in (aq) and pink/violet in hexane
      • Hydrogen-Halides
        • Production
          • All can be made by adding conc H3PO4(aq) to a solid ionic halide
          • Only HCl can be made from H2SO4(aq)
            • Iodine and bromine are strong enough reducing agents to reduce the sulfur
              • Bromide ions oxidise to Br2(g) and the sulfuric acid is reduced to SO2(g)
              • Iodide oxides to I2(g) and sulfuric acid is reduced to H2S
        • Reactions
          • Dissolve in water to form strong acids (except HF which doesn't fully dissociate so is weak acid)
          • React with ammonia to form an ammonium halide
            • E.g. HF(aq) + NH3(aq) --> NH4F(aq)
          • HBr and HI reduce H2SO4(aq)
            • HBr reduces H2SO4 to SO2
            • HI reduces H2SO4 to H2S
        • Thermal stability
          • Stability decreases down G7 due to decreasing strength of Hydrogen-Halide bonds. Halogen atoms get bigger down the group so bonding electrons further from nucleus
      • Haloalkanes
        • Boiling points
          • Increase down G7 since number of IDIDS increase
        • Reactions
          • Undergo nucleophilic substitution with OH-,H2O and NH3
        • Reactivity
          • Although the C-F bond is the most polar it has the highest bond enthalpy so reactivity increases down the group
        • Formation

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all The Periodic Table resources »