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Chemistry - Coggle Diagram

- - - - What are group 2 metals called
        
        They are called the alkaline earth metals
        
        They are similar but are less reactive
        
        group 2 metals are found in the s-block
      - Trends in physical properties
        
        Atomic radius
        
        it will decrease down the group
        
        Firs ionisation energy
        
        it will increase down the group
        
        melting point
        
        it will decrease down the group
      - Reaction with water
        
        group 2 metals are oxidised when they react with water
        
        when they react with water , they will get more reactive
        
        group 2 metals will always react with 2 moles of water.
        
        more
        
        magnesium and water
        
        magnesium hydroxide and hydrogen are produced
        
        used in indigestion
        
        reacts very slowly with water
        
        magnesium and steam
        
        magnesium oxide and hydrogen is are produced
        
        reaction occurs quickly compared with water
        
        Barium and water
        
        no reaction occurs as it is the least reactive
        
        calcium and water
        
        calcium reacts more vigorously compared to barium and magnesium.
        
        calcium hydroxide and hydrogen are produced
        
        slack slime is produced and is used to treat acidic soil
        
        strontium/barium and water
        
        react very vigorosly
      - solubility
        
        OH
        
        solubility increases down the group
        
        Sr(OH) is soluble
        
        Ca(OH)2 is sparingly soluble
        
        Ba(OH) IS soluble
        
        Mg(OH)2 is insoluble
        
        SO4
        
        solubility decreases down the group
        
        CaSO4 is slightly soluble
        
        MgSO4 IS soluble
        
        SrSO4 is slightly soluble
        
        BaSO4 is insoluble
      - Test for sulphate ions
        
        2 - add barium chloride to the solution
        
        3 - if sulphate is present , barium chloride will form
        
        1 - acidify solution with nitric or HCl
      - Uses
        
        baruym meals
        
        estraction of titanium
        
        neutralising acids
        
        CaOH slack slime
        
        Mg(OH) indigestion releif
        
        removal of flue gasses
    - - Trends in oxidising ability
        
        they are oxidising agents and they will be reduced in the process
      - displacement reactions
        
        chlorine will displace both bromine and iodine
        
        bromine will displace iodine
        
        iodine does not displace anything
      - physical properties
        
        colours
        
        florine - pale yellow
        
        chlorine - pale green
        
        chlorine - green
        
        bromine - brown
        
        why is Florine so untypical
        
        F-F bond angle is weak
        
        small size of atom leads to replusion
        
        Electronegativity
        
        decreased down the group
        
        the tendency to attract a bonding pair electron and larger atoms will attract electrons less
        
        boiling point
        
        decreases
        
        larger atoms will have more electrons and make the van der vaals forces stronger.
        
        Melting point
        
        decreases
    - - halide ions are reducing agents
        
        halide ions are oxidisings
      - why does the reducing ability of halides increase down the group
        
        halide ions will get bigger and so their
      - Reactions
        
        all will react with NaHSO4 to produce NaHSO4 and HX to produce white steamy fumes
        
        Br and I will react to produce bromine and iodine gas as well as sulphate and water
      - testing for halides
        
        1 - add HNO3
        
        to remove any unreacted carbonates
        
        2 - add drops of silver nitrate
        
        3 - observe colour precipitate
        
        AgBr - cream
        
        AgCl - white
        
        AgI - Yellow
        
        4 - add ammonia to conforms
        
        Br - disolves
        
        I - insoluble
        
        cL- - disolves
      - Chlorine
        
        used to make bleach
        
        Reacts in a disproportionation reaction
        
        Used to treat water
        
        Is toxic
    - - why does atomic radius decrease across a period
        
        electrons are pulled closer to the nucleus
        
        proton number increases so nuclear charge increases
      - Trends in melting pounts
        
        Si
        
        Giant covalent
        
        have to break strong covalent bonds
        
        P4 - Cl
        
        Simple molecular
        
        Na - Al is metalic
        
        there exists strong forces between metal ions and delocalised electrons
        
        A
        
        Monotonic
      - Why does melting point increase form NA to Al
        
        metallic bonding gets stronger
        
        metals have an increased charged
        
        Increased number of delocalised electrons
      - Why does silicon have the highest boiling point
        
        A lot of energy is needed to break the bonds
        
        Macromolecular structure with strong covalent bonds holding together
      - explain the trends between P and Ar
        
        S8 is the biggest molecules
        
        Simple molecular substance with only van der vals forces between the molecyles
    - - Why MgO have a higher melting point that Na2
        
        Magnesium forms 2+ ions which are attracted to the oxide ions more strongly to form Na2O
      - why does AlO3 have a lower melting point than MgO
        
        there exists a difference in electronegativity between Al and O
        
        O ions in Al2O3 can not attact more strongly
        
        AlO3 is partially covelant
      - Compare the structures of NaO , MgO and AlO3
        
        lots of energy needed to break the strong electrostatic forces of attraction
        
        giant ionic lattices
      - SiO3
        
        High melting point
        
        Lots of energy needed to break the strong covalent bonds
    - - transition metals are metals which form one or more ions that have an incomplete subshell
      - Why are scandium and zinc not transition metlas
        
        Scandium will have an empty subshell
        
        Zinc will only form a full subshell
      - Physical property
        
        High density and high melting and boiling point
      - Characteristics
        
        complex ion formation
        
        they will form coloured ions
        
        they will have variable oxidation states
        
        they will have catalytic activity
      - formation of coloured ions
        
        Why are transition metals coloured
        
        colour is absorbed and the remaining wavelenth is reflected
        
        electrons in the d electrons go from the ground state to an excited state