OLD QUESTION PAPERS

Class 12 CBSE Chemistry Test Paper

1

Blood cells collapse when suspended in saline water. Account for it.

(1)

2

Name any two neutral oxides.

(1)

3

a) What is the principle behind reverse osmosis?

b) Which substance is usually added into water in the car radiator to act as antifreeze?

(2)

4

State Raoult’s law for a solution containing non-volatile solute.

(2)

     

5

Complete the following equations and also balance them.

i) NH4Cl + Ca(OH)2 clip_image002

ii) Zn + HNO3 clip_image004

iii) P4 + SOCl2clip_image004[1]

iv) MnO4 + HClclip_image006

(2)

6

Draw the structures of the following compounds.

i) Peroxodisulphuric acid

ii) Phosphorous acid and account for the basicity of phosphorous acid.

(2)

7

45 g of ethylene glycol ( C2H6O2) is mixed with 600g of water. Calculate (a) the freezing point depression and (b) the freezing point of the solution.

(3)

8

2 g of benzoic acid (C6H5COOH) dissolved in 25 g of benzene shows a depression in freezing point equal to 1.62 K. Molal depression constant for benzene is 4.9 K Kgmol-1. What is the percentage association of acid if it forms dimer in solution?

(3)

9

Arrange the following in the order indicated.

i) MF, MCl, MBr, MI – Decreasing ionic character.

ii)HOCl, HOBr, HOI – increasing acidic strength

iii)NH3, AsH3, SbH3, PH3 – Decreasing bond dissociation enthalpy

(3)

10

Give reasons for the following observations.

i)Halogens are strong oxidizing agents

ii)Noble gases have large positive electron gain enthalpy.

iii)Sulphur shows paramagnetic character in vapour phase.

(3)

11

How do you prepare XeO3 from XeF4? Write equation. Draw the structure of XeF6. Mention any two applications of He gas.

(3)

12

i) How is O3 estimated quantitatively?

ii)H2SO4 is a moderately strong acid. Give evidence.

ii)Though N2 exhibits +5 oxidation state, it doesnot form pentahalide. Why?

iv)Mention the conditions required for the maximum yield of NH3.

v)What happens when Cl2 reacts with excess NH3 and NH3 reacts with excess Cl2. Give equations.

(5)

13

i) With the help of a graph explain positive deviation.

ii)The vapour pressure of pure liquids A & B are 450 & 700mm Hg respectively at 350K. Find out the composition of the liquid mixture if total vapour pressure is 600mm Hg. Also find the composition of the vapour phase.

(5)

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CBSE Chemistry Class 11 (Mid Term Exam Model Paper)

CLASS:XI CHEMISTRY

Duration: 3 hrs Maximum marks: 70

General Instructions:

All questions are compulsory.

i)Marks for each question are indicated against it.

ii)Question numbers 1 to 8 are very short answer questions and carry 1 mark each.

iii)Question numbers 9 to 18 are short answer questions and carry 2 marks each.

iv)Question numbers 1 9 to 27 are also short answer questions and carry 3 marks each.

v)Question numbers 28 to 30 are long answer questions and carry 5 marks each.

vi)Use logarithm tables if necessary. Use of calculator is not allowed.

Questions:-

1 Calculate the number of moles in 14g of N2 molecule. (1)
2 What would be the IUPAC and symbol for the elements with atomic numbers 121 and 113. (1)
3 Draw the Lewis dot structure of Nitrite ion (NO2). (1)
4 What do you meant by bond length? (1)
5 Define coefficient of viscosity. What is its S.I. unit? (1)
6 Calculate the oxidation number of phosphorous in H3P2O7and Au in HAuCl4. (1)
7 How the presence of H ions be confirmed in ionic hydrides? (1)
8 What do you understand by the term hydrogen economy ? (1)
9 Chlorine is prepared in the laboratory by treating MnO2 with aqueous HCl according to the reaction:

clip_image001[4]4HCl(aq) + MnO2 (s) 2H2O (l) + MnO2(aq) + Cl2(g)

How many grams of HCl react with 5.0 g of MnO2?

(OR)

clip_image002[6]Calcium carbonate reacts with aqueous HCl to give CaCl2 and CO2 according to the reaction, CaCO3 (s) + 2HCl(aq) CaCl2 (aq) + CO2 (g) +H2O (l).

What mass of CaCO3 is required to react completely with 25ml of 0.75 M HCl?

Atomic mass of Mn=25,Ca=20 Read more…

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CHEMISTRY SAMPLE QUESTION PAPER FOR PRACTICE

SUBJECT : CHEMISTRY CLASS – XII MAX. MARKS : 70 TIME : 3 HRS.

Instructions

· Answer all questions.

· Questions 1 to 8 carry one mark each. Answer them in one word or sentence.

· Questions 9 to 18 are short answer questions and carry two marks each.

· Questions 19 to 27 are also short answer questions and carry three marks each.

· Questions 28 to 30 are long answer questions and carry 5 marks each.

1. What are the physical state of dispersed phase and dispersion medium of emulsion?

2. The formula of a compound is A2B3 with a hcp lattice. What fraction of tetrahedral voids are occupied?

3. What is the purpose of adding xanthates to sulphide ores?

4. What is the charge on the sol formed when KI is added to excess AgNO3?

5.

CH3

Pentavalent Bismuth is a strong oxidizing agent. Why?

clip_image001

6. Write IUPAC name of

7. What is carbylamine reaction?

8. Both cellulose and starch are made up of glucose units. Starch can be digested by humans but cellulose cannot be digested. Why?

9. (i) What is the reason for abnormal molecular mass of solute?

(ii) A person suffering from high blood pressure should take less common salt. Why?

10. Give reason

a) 1 gm. of pulverized wood burns faster than 1 gm. of a piece of wood.

b) Reactions of higher molecularity are rare.

11. How will you distinguish between o/w and w/o emulsions? Read more…

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AISSCE CHEMISTRY OLD QUESTION PAPERS 2007

WE ARE PROVIDING EIGHT SETS OF AISSCE CHEMISTRY 2007 QUESTION PAPERS FRO YOU TO PRACTICE

AISSCE CHEMISTRY 2007  QP SET 1

AISSCE CHEMISTRY 2007 QP SET 2

AISSCE CHEMISTRY  2007 QP SET 3

AISSCE CHEMISTRY2007  QP SET 4

AISSCE CHEMISTRY 2007 QP SET 5

AISSCE CHEMISTRY 2007 QP SET 6

AISSCE CHEMISTRY 2007 QP SET 7

AISSCE CHEMISTRY 2007 QP SET 8

1 comment - What do you think?  Posted by admin - March 6, 2011 at 10:00 pm

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