NDA CHEMISTRY PAST QUESTION 10.

Check questions 1 – 20 here

21.  The acid which occurs in ants, stinging betties, pine needles and bees is:
A.  Benzoic acid
B.  Acetic acid
C.  Salicylic acid
D.  Formic acid

22.  Bohr’s model of the atom can be used to explain:
A.  emission between energy levels
B.  radiation in the molecular state
C.  emission in the octahedral atom
D.  the emission from un-ionized atoms

23.  Crystals in which all the atoms are linked by a continuous system of well–    defined electron pair bonds are called:
A.  Diamond network solids
B.  Dative–valence solids
C.  Covalent network solids
D.  Ionic network solids

24.  Which of the following is/are true of Avogadro number?
A.    The mass which contains one mole differs for various substances
B.    The mass of 1g contains 6.02 x 1023 ions
C.    The mass which contains one mole is the same for various substances
D.   The mass which contains one mole is equal 2/3 of C- 12

25.  The heat change associated with a given chemical change is always constant and is independent of time and of any intermediate changes involved. This is
A.    Dalton’s law of heat summation
B.    Hess’s law of heat summation
C.    Dulon & Patil law of heat summation
D.    Born-haler law of heat summation

26.  Electro-valent bond is best favoured by:
A.    A large metallic atom and a small non-metallic atom
B.    A small stable atom
C.    A large anion which loses electrons
D.    Resonance in the bonding pairs

27.  Which of the following is most correct of a double salt?
A.    Contains at least two different cations other than H+
B.    Contains many cations and anions
C.    Contains metallic cations and anions derived from acids
D.    Ionise to produce complex ions

28.  The normal boiling point of a liquid is the temperature at which:
A.    the vapour of the liquid equals 740mm Hg
B.    the vapour pressure of the liquid equals 760mm Hg
C.    the vapour pressure of the liquid is less than the external pressure of                0.85
D.    the vapour of the liquid equals 740mm Hg

29.  In carbon atom, the wave functions for the respective electrons can be represented thus.
A.    1 (S + Px + Py + Pz)
B.    1 (S + Px – Py – Pz)
C.    S (Px – Py – Pz)
D.     1 (S – Px – Py + Pz)

30.  The formula CH2O for ethanoic acid is regarded as its____
A.   empirical formula
B.   molecular formula
C.   Structural formula
D.   general formula

31. Which of the following gases contains the least number of atoms at s.t.p.?
A.   7 moles of argon
B.   4 moles or chlorine
C.   3 moles of ozone
D.   1 mole of butane

32.  The chromatographic separation of ink is based on the ability of the            components to
A. dissolve in each other in the column
B. move at different speeds in the column
C. react with the solvent
D. react with each other.

33.  A compound contains 31.91% potassium 28.93% chlorine and the rest oxygen. What is the chemical formula of the compound?
A.  KClO
B.  KClO2
C.  KClO3
D.  KClO4

34. A little quantity of trichloromethane (b.pt 60°C) was added to a large quantity of ethanol (b.pt.78 °C-74 °C). The most probable boiling point of the    resultant mixture is from
A. 60°C – 78°C
B. 69°C – 70°C
C. 70°C – 74°C
D. 82°C – 84°C

35. The gas that gives brown colouration in brown ring test is
A. CO
B. NO
C. CO2
D. NO2

36. Which of the following gives a precipitate when treated with NaOH solution?
A. NH4Cl
B. Na2CO3
C. AlCl3
D. CH3COONa

37. The reaction of an alkene with hydrogen in the presence of a catalyst is
A. a nucleophilic reaction
B. an addition reaction
C. a substitution reaction
D. an oxidative reaction

38. A rock sample was added to cold dilute HNO3. The gas evolved was passed into a solution of acidified K2Cr2O7 and the solution turned green. The rock sample contains
A. SO4 2-
B. SO3 2-
C. NO3-
D. Cl-

39. The intermediate product formed when ethanol is progressively oxidized to ethanoic acid with potassium heptaoxodichromate (VI) is
A. methanol
B. propanal
C. ethanal
D. butanal

 

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