Sample Test 16

Analysis of Solid F

Test Procedure

You are provided with solid F. Carry out the tests below. Write your observations and inferences in the spaces provided below.

  • (a)
      (i)Place solid F in a boiling tube and add about 10cm3 of distilled. Filter and divide the filtrate into four portions. Keep the residue for part b
    • (ii)To the 1st portion, add sodium hydroxide dropwise till in excess
    • (iii)To the 2nd portion, add ammonia solution dropwise till in excess
    • (iv) To the 3rd portion, add few drops of lead (ii) nitrate
    • (v) To the 4th portion, add few drops of barium nitrate solution
  • (b) Put the residue in a clean boiling tube and add nitric (v) acid little by little until it just dissolves. Divide the solutions into two portions
    • (i)To the 1st portion, add sodium hydroxide dropwise till in excess
    • (ii)To the 2nd portion, add ammonium solution dropwise till in excess

      Tips: To start, ...click on boiling tube in the display rack to select it before placing the sample.
      Follow the procedure sequentially and the sytem monitor instructions.

      Tips on the system color code

      Colourless Solution

      White Precipitate

    Workbench

    VIRTUAL WORKBENCH MONITOR Selected: None
    System Initialised. Select boiling tube to start step 1.
    Main
    T₁
    T₂
    T₃
    T₄
    Main
    T5
    T6

    STUDENT LABORATORY WORKBOOK

    Procedure Observations Inferences
    (a) (i) Solid F in boiling tube + 10cm3 distilled water, filtered & divided into 4 portions.
    (ii) 1st portion + NaOH till in excess
    (iii) 2nd Portion + NH4OH solution dropwise till in excess
    (iv) 3rd portion + few drops of Pb(NO3) solution
    (v) 4th portion + few drops of Ba(NO3)2 solution
    (b)Residue in a clean boiling tube + dilute HNO3
    (i) 1st portion + NaOH dropwise till in excess
    (ii) 2nd portion + NH4OH dropwise till in excess

    OFFICIAL MARKING SCHEME & EXPECTED RESPONSES

    Procedure Observations Inferences
    (a) (i) Solid F in boiling tube + 10cm3 distilled water, filtered & divided into 4 portions. Blue solution. White residue

    (1 mark)     		F is a mixture of soluble & insoluble salt

    (1mark)
    (ii) 1st portion + NaOH till in excess Blue precipitate insoluble in excess

    (1 Mark)     		Cu2+ present

    (1 mark)
    (iii) 2nd Portion + NH4OH solution dropwise till in excess Blue precipitate soluble in excess to give a blue solution

    (1 mark)     		Cu2+ confirmed present

    (1 mark)
    (iv) (iv) 3rd portion + few drops of Pb(NO3) solution White prcipitate

    (1 mark)     		SO32-, SO42-, CO32-, Cl- present

    (1 mark)
    (v) 4th portion + few drops of Ba(NO3)2 solution No White precipitate

    (1 mark)     		Cl- present.
    (vi) 5th portion + BaCl2 solution No White precipitate

    (1 mark)     		SO42- absent.

    (1 mark)
    (vii) 6th portion + aluminium foil + NaOH + Warming + red & blue litmus paper Effevescence of a gas that turns red litmus paperblue and no effet on blue ltmas paper

    (1 mark)     		NO3- present.
    (b)Residue in a clean boiling tube + dilute HNO3 Effevescence of a colourless ordourless gas.

    (1 mark)     		CO3- present.
    (i) 1st portion + NaOH dropwise till in excess White precipitate insoluble in excess.

    (1 mark)     		Mg2+, Ca2+, Ba2+ present.
    (ii) 2nd portion + NH4OH dropwise till in excess No White precipitate.

    (1 mark)     		Ca2+ present.

    Identity of solid F- CaCO3+CuCl2