ICSE CHEMISTRY - PRACTICE PAPER 15

ICSE CHEMISTRY - PRACTICE PAPER 15

Question 1                                                                                                                  3+3+4

a)      Identify the role played by Conc. Sulphuric acid in the following reactions:

i)        3S + 2H₂SO₄ à 3SO₂ + 2H₂O

ii)      CuSO₄ .5H₂O + Conc.H₂SO₄  à   CuSO₄ +5H₂O

iii)    C₁₂H₂₂O₁₁   Conc.H₂SO₄   à  12C + 11H₂O

b)      State your observations seen when:

i)        Conc. Sulphuric acid is added to Copper oxide.

ii)      Dil. Suplhuric acid is added to Barium chloride solution.

iii)    Conc. H₂SO₄ is added to blue copper sulphate.

c)      i) Name the gas released when Sulphur is treated with  Conc. Sulphuric acid.

ii) Write balanced equation for the conversion of SO₂ to SO₃ in Contact process with conditions if any.

Give balanced equations for the reactions :

iii) dil.H₂SO₄ reacts with ZnO

iv) Copper to Copper sulphate using Conc. Sulphuric acid.

Question 2                                                                                                           3+3+2+2

a)      i) Name the reactants used in the preparation of HNO₃ in the laboratory method.

ii) Give balanced  equation for the above preparation and mention the conditions required.

iii) Mention any one precaution to be taken during above process.

b)      Give reason why :

i) The temperature should be maintained below 200⁰C in the above process.

ii) Entire apparatus is made of Glass

iii) HNO₃ prepared in the laboratory appears yellowish brown.

c)      Give balanced equations for:

i) Reaction between Conc.HNO₃ and Carbon

ii) Decomposition of HNO₃ on heating.

d)     State the observations seen when the following compounds are heated :

i) Pb(NO₃)₂                               ii) Cu(NO₃)₂