Wednesday, February 13, 2013

PPSC Past Papers of Chemistry

12.  The hydrogen molecule may be represented by two wave functions, Ψcovalent and Ψionic and C1and C2are
coefficient indicating the weight of each function. The real wave function may be written as (N is the
normalization constant)
(a)  Ψ= N [Ψcovalent+ Ψionic]  (b)  Ψ= N [C1 Ψcovalent+ C2 Ψionic]
(c)   Ψ= N [C1 Ψcovalent x C2 Ψionic]  (d)  Ψ= (C1 + C2 ) N [Ψcovalent x C2 Ψionic]
(e)None of these
13.  Copper metal will replace silver ions in solution, resulting in the production of silver metal and copper ions. This
indicates that:
(a)Silver has a higher oxidation potential than copper. (b)A combustion reaction is occurring.
(c) Copper has a higher oxidation potential than silver. (d)Silver is much less soluble than copper.
(e)None of these
14.  According to Debye-Huckel theory of strong electrolytes,and ion moving in an atmosphere of oppositely charged
ions experiences a drag. This effect is known as the:
(a)Asymmetric effect  (b)Electrophoretic effect  (c) Inter-ionic effect
(d)Concentration effect  (e)None of these
15.  The electrical conductivity of an electrolyte depends upon:
(a)The number of molecules in the electrolyte.  (b)The number of ions present in the electrolyte.
(c) The number of ions present in the solution .  (d)The number of molecules of the solvent.
(e)None of these
16.  Brass is an alloy of:
(a)Cu and Zn  (b)Cu, Ni, Zn  (c) Cu and Ni  (d)Cu, Al, Zn (e)None of these
17.  Urea is a high quality nitrogenous fertilizer with:
(a)76% nitrogen  (b)46% nitrogen  (c) 66% nitrogen  (d)26% nitrogen  (e)None of these
18.  When Zn metal is kept in CuSO4 solution, copper is precipitated and ZnSO4is formed because:
(a)Atomic number of Zinc is smaller than copper.  (b)Atomic number of Zinc is larger than copper.
(c) Standard reduction potential of Zinc is more than that of copper.
(d)Standard reduction potential of Zinc is less than that of copper.  (e)None of these
19.  The most important ore of aluminium is:
(a)Bauxite  (b)Magnetite  (c) Haematite  (d)Monazite  (e)None of these
20.  The inexpensive and commonly used variety of glass is called soda glass. It is called so because:
(a)Was used initially for making bottles of soda (carbonated drink). (b)Is made using soda (sodium carbonate)
(c) Was initially used for storing sodium carbonate.  (d)Is made using soda lime.  (e)None of these


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