ISC 2019 Chemistry Practical Question Paper for Class 12

About this paper

This is ISC Class 12 Chemistry Paper 2 (Practical), code 862B, from the 2019 examination. It carries 30 marks and runs for three hours plus fifteen minutes of reading time, and mathematical tables are provided. All four questions are compulsory. Question 1 titrates impure oxalic acid against potassium manganate(VII): C-10 contains 2.80 g of KMnO₄ per litre and C-11 is prepared from 6.25 g of impure H₂C₂O₄·2H₂O per litre. Candidates calculate both molarities, the strength and the percentage purity. Question 2 identifies an organic compound and tests whether a second sample is a carbohydrate or a protein. Question 3 finds one anion and one cation in salt C-15, without a qualitative analysis table. Question 4 is the project and the Chemistry practical file. This copy has the questions only.

Exam

ISC Class 12

Subject

Chemistry Practical

Year

2019

Paper code

862B

Maximum marks

30

Time allowed

3 hours + 15 min reading

Questions

4

Pages

4

Answers included

No, questions only

Paper pattern

• Question 1

  7 marks

  Redox titration of impure oxalic acid with potassium manganate(VII), with molarity, strength and percentage purity to be calculated

• Question 2

  4 marks

  Identification of organic compound C-13, and tests to decide whether C-14 is a carbohydrate or a protein

• Question 3

  4 marks

  Qualitative analysis of C-15, which contains one anion and one cation; a qualitative analysis booklet or table is not allowed

• Question 4

  15 marks

  Project (10 marks) and Chemistry practical file (5 marks), shown to the Visiting Examiner

Topics covered

• Redox titration
• Potassium permanganate
• Oxalic acid
• Percentage purity
• Identification of an organic compound
• Tests for carbohydrate and protein
• Qualitative analysis of an anion and a cation
• Project and practical file

Questions from this paper

1. C-10 contains 2.80 g of potassium manganate(VII) per litre, and C-11 is prepared by dissolving 6.25 g of impure oxalic acid crystals (H₂C₂O₄·2H₂O) per litre. Calculate the molarity of each solution, the strength of the oxalic acid in grams per litre, and the percentage purity of the sample.
2. Warm the oxalic acid solution, after adding dilute sulphuric acid, to 60°C–70°C until the first bubble appears, then titrate it with KMnO₄ to a permanent pale pink colour. Molarity must be calculated to at least four decimal places.
3. For organic compound C-13, add sodium hypochlorite, test a portion with concentrated hydrochloric acid and neutral ferric chloride, and warm another portion with dilute sulphuric acid and potassium dichromate.
4. C-14 is either a carbohydrate or a protein. Test separate portions with Fehling's solution, with α-naphthol and concentrated sulphuric acid, and with lead acetate followed by ammonium hydroxide, and state which it is.
5. Identify the one anion and the one cation in C-15. For the anion, state how the gases were identified and give the confirmatory test. A qualitative analysis table is not allowed.