CBSE Set Set3 Chemistry Sample Test Papers For Class 12th for students online

Chemistry Class - XII  (CBSE)
You are on questions of Set III
(Only those questions are given,which are different from Set I
and Set II)

Q.2 In the rock salt structure how many Na⁺ ions occupy second-nearest neighbour location of a Na⁺ ion? (1 mark)


Q.3 Which type of hybridisation explains the trigonal bipyramidal shape of SF_4? (1 mark)


Q.11 Calculate the uncertainty in the velocity of a wagon of mass 3000 kg whose position is known to an accuracy of 10pm. (h = 6.63 x 10^-34.Js)
(1 mark)


Q.12 (i) What is the basic building unit of all silicates?
(ii) How many oxygen atom of this unit are shared with others in the silicate ion Si₃O₉^6- ion. (1 mark)


Q.23 Draw the structure and write the hybridisation state of the central atom of each of the following species :
(i) [Co(NH₃)₆]³⁺
(ii) [NiCl₄)]^2-) (1 mark)


Q.27 (i) Using the data given below calculate the value of equilibrium constant for the reaction 3HC = CH^(g) <=== C₆H_6(g) at 298 K, issuing ideal gas behaviour.
G ^o_f HC = CH_(g) = 2.09 x 10⁵ J mol^-1
G ^o_f C₆H_6(g) = 1.24 x 10⁵ J mol^-1
R = 8.314 J K mol^-1
(ii) Based on your calculated value, comment whether this process can be recommended as a practical method for making benzene. (3 marks)


Q.29 Give the reasons for the following features of transition metal chemistry.
(i) The lowest oxide of a transition metal (say chromium, atomic number 24 ) is basic whereas the highest oxide is usually acidic.
(ii) Transition metals sometimes exhibits very low oxidation states such as +1 and 0.
(iii) Zirconium (atomic number 40) and Hafnium (atomic number 72) occur together in minerals and they exhibits similar properties. (5 marks)


Q.34 (a) "The first element in a group of p-block of the periodic table often displays different physical and chemical properties from the behaviour members of the group". In the light of this statement give comparative explanations for the following :
(i) Nature of oxides of boron and aluminium.
(ii) Action of water on CCl₄ and SiCl₄.
(iii) Structure's of N₂O₅ and P₄O₁₀.
(iii) Maximum numbers of covalency exhibited by oxygen and sulphur.

(b) Explain the shape of XeF₄ on the basis of VSEPR theory. (5 marks)