NCERT CHEMISTRY PRACTICALS–12TH CLASS

PRACTICALS                                                      Total Periods 60

Micro-chemical methods are available for several of the practical experiments. Wherever possible such techniques should be used.

A. Surface Chemistry                                       (Periods 5)

(a) Preparation of one lyophilic and one lyophobic sol.

Lyophilic sol : starch , egg albumin and gum.

Lyophobic sol : aluminium hydroxide, ferric hydroxide, arsenious sulphide.

(b) Dialysis of sol prepared in (a) above.

(c) Study of the role of emulsifying agent in stabilizing the emulsions of different oils.

B. Chemical Kinetics                                        (Periods 4)

(a) Effect of concentration and temperature on the rate of reaction between sodium thiosulphate and hydrochloric acid .

(b) Study of reaction rates of any one of the following:

(i) Reaction of iodide ion with hydrogen peroxide at room temperature using different concentrations of iodide ions.

(ii) Reaction between potassium iodate (KIO₃) and sodium sulphite (Na₂SO₃) using starch solution as indicator (clock reaction).

C. Thermochemistry                                         (Periods 4)

Any one of the following experiments :

(a) Enthalpy of dissolution of copper sulphate or potassium nitrate.

(b) Enthalpy of neutralization of strong acid (HCl) and strong base (NaOH)

(c) Determination of enthalpy change during interaction (Hydrogen bond formation) between acetone and chloroform.

D. Electrochemistry                                           (Periods 2)

Variation of cell potential in Zn/Zn2+//Cu2+/Cu with change in concentration of electrolytes (CuSO4 or ZnSO4) at room temperature.

E. Chromatography                                            (Periods 2)

(a) Separation of pigments from extracts of leaves and flowers by paper chromatography and determination of Rf values.

(b) Separation of constituents present in an inorganic mixture containing two cations only (constituents having wide difference in Rf values to be provided).

F. Preparation of Inorganic Compounds (Periods 4)

(a) Preparation of double salt of ferrous ammonium sulphate or potash alum.

(b) Preparation of potassium ferric oxalate.

G. Preparation of Organic Compounds (Periods 2)

Preparation of any one of the following compounds:

(a) Acetanilide

(b) Di-benzal acetone

(c) p-Nitroacetanilide

(d) Aniline yellow or 2 - Napththol aniline dye

H. Test for the Functional Groups Present in Organic Compounds               (Periods 5)

Unsaturation, alcoholic, phenolic, aldehydic, ketonic, carboxylic and amino (primary) groups.

I. Characteristic Tests of Carbohydrates, Fats and Proteins in Pure Samples and Their Detection in Given Food Stuffs.                                                                                                (Period 4)

J. Determination of Concentration/Molarity of KMnO4 Solution by Titrating it against a

Standard Solution of –                                             (Periods 10)

 (i) Oxalic acid

(ii) Ferrous ammonium sulphate

(Students will be required to prepare standard solutions by weighing themselves).

K. Qualitative Analysis                                            (Periods 16)

• Determination of one cation and one anion in a given salt.

Cations -  Pb²⁺ ,Cu²⁺ ,As²⁺ ,Al²⁺ ,Fe²⁺ ,Mn²⁺ ,Ni²⁺ ,Zn²⁺ ,Co²⁺ ,Ca²⁺ ,Sr²⁺ ,Ba²⁺ ,Mg²⁺ ,(NH₄)²⁺

Anions – (CO₃)^2-,S^2-,(SO₄)^2-,(NO₂)^-,(NO₃)^-,Cl^-,Br^-,I^-,(PO₄)^3—,(C₂ O₄)-, CH₃ COO^-

(Note : Insoluble salts excluded)