ISC 2018 Chemistry Practical Question Paper for Class 12

About this paper

This is ISC Class 12 Chemistry Paper 2 (Practical), code 862B, from the 2018 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 hydrated ammonium iron(II) sulphate, (NH₄)₂SO₄·FeSO₄·xH₂O, against potassium manganate(VII). C-10 contains 1.95 g of KMnO₄ per litre and C-11 contains 23.2 g of the salt per litre. The candidate finds both molarities, the experimental molecular mass and the value of x. Question 2 identifies two organic compounds, and Question 3 finds the one anion and one cation in salt C-15. A qualitative analysis table is not allowed. Question 4 is the project and the Chemistry practical file. This copy has the questions only.

Exam

ISC Class 12

Subject

Chemistry Practical

Year

2018

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 hydrated ammonium iron(II) sulphate with potassium manganate(VII), including the experimental molecular mass and the value of x

• Question 2

  4 marks

  Identification of two organic compounds, C-13 and C-14, from the tests given

• 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
• Hydrated ammonium iron(II) sulphate
• Water of crystallisation
• Identification of organic compounds
• Qualitative analysis of an anion and a cation
• Project and practical file

Questions from this paper

1. C-10 contains 1.95 g of potassium manganate(VII) per litre, and C-11 is prepared by dissolving 23.2 g of hydrated ammonium iron(II) sulphate, (NH₄)₂SO₄·FeSO₄·xH₂O, per litre. Find the molarity of each solution, the molecular mass of the hydrated salt from the experiment, and the value of x.
2. Pipette out 20 ml or 25 ml of C-11, add 20 ml of dilute sulphuric acid, and titrate with KMnO₄ until one drop gives a light permanent pink colour. Record at least two concordant readings.
3. For organic compound C-13, add a few crystals of resorcinol and concentrated sulphuric acid, test it with freshly prepared pyrogallol and concentrated hydrochloric acid, and warm it with Tollen's reagent.
4. For C-14, add a few drops to 1% borax solution containing phenolphthalein; heat a portion with phenol and concentrated sulphuric acid, then dilute and add ammonium hydroxide; and add copper sulphate solution followed by sodium hydroxide.
5. Identify the one anion and the one cation in substance C-15. Describe how the soda extract and the original solution were prepared, and give the confirmatory test for each ion. A qualitative analysis table is not allowed.