CBSE Chemistry Practical For Class 12

CBSE Chemistry Practical For Class 12

 

PRACTICALS

 

Evaluation Scheme for Examination Marks
Volumetric Analysis 08
Salt Analysis 08
Content Based Experiment 06
Project Work 04
Class record and viva 04
Total 30

 

 

PRACTICAL SYLLABUS                                                                                                           36 Periods

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

 

 

A.Chromatography

  1. Separation of pigments from extracts of leaves and flowers by paper chromatography and determination of Rf
  2. Separation of constituents present in an inorganic mixture containing two cations only (constituents having large difference in Rf values to be provided).

 

A.       Preparation of Inorganic Compounds

Preparation of double salt of Ferrous Ammonium Sulphate or Potash Alum. Preparation of Potassium Ferric Oxalate.

 

B.       Tests for the functional groups present in organic compounds:

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

C.      Characteristic tests of carbohydrates, fats and proteins in pure samples and their detection in given foodstuffs.

  1. Determination of concentration/ molarity of KMnO4 solution by titrating it against a standardsolution of:
    1. Oxalic acid,
    2. Ferrous Ammonium Sulphate

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

E.        Qualitative analysis

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

4

Cation : Pb2+, Cu2+ As3+, Aℓ3+, Fe3+, Mn2+, Zn2+, Cu2+, Ni2+, Ca2+, Sr2+, Ba2+, Mg2+, NH +

3

Anions: (CO3)2-, S2-, (SO3)2-, (NO2)-, (SO4)2-, Cℓ, Br, I, PO3- 4, (C2O4)2-, CH3COO,NO –

(Note: Insoluble salts excluded) PROJECT

Scientific investigations involving laboratory testing and collecting information from other sources

A few suggested Projects.

  • Study of the presence of oxalate ions in guava fruit at different stages of
  • Study of quantity of casein present in different samples of
  • Preparation of soybean milk and its comparison with the natural milk with respect to curd formation, effect of temperature,
  • Study of the effect of Potassium Bisulphate as food preservative under various conditions (temperature, concentration, time, )
  • Study of digestion of starch by salivary amylase and effect of pH and temperature on
  • Comparative study of the rate of fermentation of following materials: wheat flour, gram flour, potato juice, carrot juice,
  • Extraction of essential oils present in Saunf (aniseed), Ajwain (carum), Illaichi (cardamom).
  • Study of common food adulterants in fat, oil, butter, sugar, turmeric power, chilli powder and pepper. Note: Any other investigatory project, which involves about 10 periods of work, can be chosen with the approval of the

 

Practical Examination for Visually Impaired Students of Classes XI and XII Evaluation Scheme

Time Allowed: Two hours                                                                                               Max. Marks:30

 

Identification/Familiarity with the apparatus 5 marks
Written test (based on given/prescribed practicals) 10 marks
Practical Record 5 marks
Viva 10 marks
Total 30 marks

 

General Guidelines

  • The practical examination will be of two hour
  • A separate list of ten experiments is included
  • The written examination in practicals for these students will be conducted at the time of practical examination of all other
  • The written test will be of 30 minutes

 

 

  • The question paper given to the students should be legibly typed. It should contain a total of 15 practical skill based very short answer type questions. A student would be required to answer any 10
  • A writer may be allowed to such students as per CBSE examination
  • All questions included in the question papers should be related to the listed practicals. Every question should require about two minutes to be
  • These students are also required to maintain a practical file. A student is expected to record at least five of the listed experiments as per the specific instructions for each subject. These practicals should be duly checked and signed by the internal
  • The format of writing any experiment in the practical file should include aim, apparatus required, simple theory, procedure, related practical skills, precautions
  • Questions may be generated jointly by the external/internal examiners and used for
  • The viva questions may include questions based on basic theory/principle/concept, apparatus/materials/ chemicals required, procedure, precautions, sources of error

 

A.       Items for Identification/Familiarity of the apparatus for assessment in practical (Allexperiments)

Beaker, glass rod, tripod stand, wire gauze, Bunsen burner, Whatman filter paper, gas jar, capillary tube, pestle and mortar, test tubes, tongs, test tube holder, test tube stand, burette, pipette, conical flask, standard flask, clamp stand, funnel, filter paper

Hands-on Assessment

  • Identification/familiarity with the apparatus
  • Odour detection in qualitative analysis

B.       List of Practicals

The experiments have been divided into two sections: Section A and Section B. The experiments mentioned in Section B are mandatory.

 

 

 

 

SECTION- A

 

  • Chromatography
    • Separation of pigments from extracts of leaves and flowers by paper chromatography and determination of Rf values (distance values may be provided).

B         Tests for the functional groups present in organic compounds:

  • Alcoholic and Carboxylic
  • Aldehydic and Ketonic

C         Characteristic tests of carbohydrates and proteins in the given foodstuffs.

  • Preparation of Inorganic Compounds- Potash Alum

 

SECTION-B (Mandatory)

 

  • Quantitative analysis
    • (a) Preparation of the standard solution of Oxalic acid of a given volume

(b)     Determination of molarity of KMnO4 solution by titrating it against a standard solution of Oxalic acid.

  • The above exercise [F 1 (a) and (b)] to be conducted using Ferrous ammonium sulphate (Mohr’s salt)

 

F           Qualitative analysis:

4
  • Determination of one cation and one anion in a given salt. Cation –NH +
3                 3                 3

Anions – CO 2-, S2-, SO 2-, Cl, CH COO

(Note: Insoluble salts excluded)

 

Note: The above practicals may be carried out in an experiential manner rather than recording observations.

Prescribed Books:

  1. Chemistry Part -I, Class-XII, Published by
  2. Chemistry Part -II, Class-XII, Published by

CBSE Biology Practical For Class 12

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