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Chemical tests (Testing for gases (Carbon Dioxide (Limewater test (Carbon…

- - - - Carbon dioxide
        turns limewater
        from clear to milky
        
        Equipment:
        
        Test tube with
        unknown substance
        
        Test tube with limewater
        
        Bung with delivery tube
        
        Method
        
        Set up the test tube with unknown substance so that it is connected to the test tube with limewater using the bung with delivery tube to allow the substance to come in contact with the limewater
        
        If the limewater turns milky then carbon dioxide is present
  - - - Chlorine turns damp
        blue litmus paper red
        then bleaches it
        
        Equipment:
        
        Test tube with
        unknown substance
        
        Blue litmus paper
        
        Method
        
        Insert the damp blue litmus paper into the test tube
        
        If the litmus paper turns red then becomes white then chlorine is present
        
        Dampen the blue litmus paper with water so that the chlorine gas would be dissolved
  - - - Hydrogen pops
        when ignites
        
        Equipment:
        
        Test tube with
        unknown substance
        
        Splint
        
        Bunsen burner/Candle
        
        Method
        
        Put the burning splint into the test tube
        
        If it produces a squeaky pop sound then hydrogen is present
        
        Light a splint on fire using the bunsen burner/candle
  - - - Ammonia turns
        damp red litmus
        paper blue
        
        Equipment:
        
        Test tube with
        unknown substance
        
        Red litmus paper
        
        Method
        
        Insert the damp red litmus paper into the test tube
        
        If the litmus paper turns blue then ammonia is present
        
        Dampen the red litmus paper with water so that the ammonia gas would be dissolved
  - - - Oxygen relights a
        glowing splint
        
        Equipment:
        
        Test tube with
        unknown substance
        
        Splint
        
        Bunsen burner/Candle
        
        Method:
        
        Light a splint on fire using the bunsen burner/candle
        
        Put out the fire on the splint to get a glowing splint
        
        Insert the glowing splint into the test tube with the unknown substance
        
        If the glowing splint relights then oxygen is present
- - - - Equipment:
        
        Unknown solution
        
        Dilute hydrochloric acid
        
        Test tube
        
        Limewater
        
        Bung with delivery tube
        
        Method
        
        Pour the unknown solution into the test tube
        
        Add the dilute hydrochloric acid into the test tube
        
        Test using limewater and a bung with a delivery tube to see if carbon dioxide is produced in the experiment
  - - - Equipment:
        
        Unknown solution
        
        Silver nitrate
        
        Nitric acid
        
        Test tube
        
        Method
        
        Add the sliver nitrate
        solution into the test tube
        
        Observations
        
        Bromide Br-
        
        Cream precipitate formed
        
        Iodide I-
        
        Yellow precipitate formed
        
        Chloride Cl-
        
        White precipitate formed
        
        A precipitate will form if
        halide ions are present
        
        Pour the unknown solution into
        the test tube and add nitric acid
        to react with the carbonates
        (if present), since carbonate ions
        also forms a white precipitate.
  - - - Equipment:
        
        Unknown solution
        
        Barium Chloride
        
        Nitric acid
        
        Test tube
        
        Method
        
        Add the barium chloride solution into the test tube
        
        A white precipitate(barium sulphate) will form if sulphate ions are present
        
        Pour the unknown solution into the test tube and add nitric acid to react with the carbonates(if present), since carbonate ions also forms a white precipitate.
- - - - Equipment:
        
        Metal ions
        
        Bunsen burner
        
        Hydrochloric acid
        
        Wire loop
        
        Method:
        
        Dip the wire loop into the
        hydrochloric acid to clean it
        
        Dip the wire loop into the
        metal ion being tested
        
        Place the wire loop on
        top of a lit bunsen burner
        
        Observe the flame colour
        created
        
        Observations
        
        Barium Ba2+
        
        Produces an apple green flame
        
        Lithium Li+
        
        Produces a red flame
        
        Potassium K+
        
        Produces a lilac flame
        
        Calcium Ca2+
        
        Produces an orange-read/brick-red flame
        
        Sodium Na+
        
        Produces a yellow flame
  - - - Equipment:
        
        Metal ion solutions
        
        Sodium hydroxide
        
        Test tube
        
        Method:
        
        Add some of the metal ion
        solution into a test tube
        
        Add the sodium hydroxide
        solution into the test tube
        
        Observe the colour of the
        precipitate produced
        
        Iron(II) Fe2+
        
        Produces a green precipitate
        
        Aluminium Al3+
        
        Damp red litmus paper turns blue
        
        Observations
        
        Iron(III) Fe3+
        
        Produces a reddish brown precipitate
        
        Calcium Ca2+
        
        Produces a white precipitate
        
        Magnesium Mg2+
        
        Produces a white precipitate
        
        Copper Cu2+
        
        Produces a light blue precipitate
- - - - Equipment:
        
        Anhydrous copper sulphate
        
        Watch glass
        
        Pipette
        
        Unknown substance
        
        Method
        
        Use the pipette to get some of the unknown substance
        
        Drop some of the unknown substance into the watch glass with anhydrous copper sulphate
        
        Put some anhydrous copper suphate into a watch glass
        
        If the anhydrous copper sulphate turns from white to blue hydrated copper sulphate then water is present