Sample Test 2

Analysis of Solid N

Test Procedure

You are provided with Solid N. Carry out the tests below and write down your observations and inferences.

  • (i)Place solid N in a boiling tube and add 12cm3 of distilled water. Divide the resulting solution into six portions.
  • (ii)To the 1st portion add 2M sodium hydroxide dropwise till in excess
  • (iii)To the 2nd portion add aqueous sodium sulphate
  • (iv)To the 3rd portion add dilute 2M Nitric (v) acid
  • (v)To the 4th portion, add lead (ii) nitrate
  • (vi)To the 5th portion add 2 drops of barium chloride solution
  • (vii)To the 6th portion, add aluminium foil followed by drops of aqueous NaOH then warm.Test the gases produced with red and blue litmus paper.

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
T5
T6

STUDENT LABORATORY WORKBOOK

Procedure Observations Inferences
(i) Solid N in boiling tube + 12cm3 distilled water, divided into 6 portions
(1 mark)
(1 mark)
(ii) 1st portion + NaOH till in excess
(1 mark)
(1 mark)
(iii) 2nd Portion + aqueous Sodium Sulphate
(1 mark)
(1 mark)
(iv) 3rd portion + dilute HNO3
(1 mark)
(1 mark)
(v) 4th portion + Pb(NO3)2
(1 mark)
(1 mark)
(vi) 5th portion + BaCl2 solution
(1 mark)
(1 mark)
(vii) 6th portion + aluminium foil + NaOH + Warming + red & blue litmus paper
(1 mark)
(1 mark)

OFFICIAL MARKING SCHEME & EXPECTED RESPONSES

Procedure Observations Inferences
(i) Solid N in boiling tube + 12cm3 distilled water, divided into 6 portions dissolves to form a colourless solution

(1 mark) 		N is a soluble salt

Fe2+, Cu2+, Fe3+ absent

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

(1 Mark) 		Ca2+, Mg2+ present

(1 mark)
(iii) 2nd Portion + aqueous Sodium Sulphate Whie precipitate

(1 mark) 		Ca2+ present

(1 mark)
(iv) 3rd portion + dilute HNO3 No effervescence

(1 mark) 		SO32-, CO32-,HCO3- absent

(1 mark)
(v) 4th portion + Pb(NO3)2 No White precipitate

(1 mark) 		SO42-, Cl- absent.
(vi) 5th portion + BaCl2 solution No White precipitate

(1 mark) 		SO42- absent.
(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.

Identity of solid N: Calcium Nitrate - Ca(NO3)2