State of Matter MCQ Solved Paper for SSC Scientific Assistant

1. The best electrical conductor of the following is
A. $C{O}_2$(s)
B. Si(s)
C. NaCl (fused)
D. $B{r}_2$(I)
Answer : C

2. For a given gas at temperature T and pressure P the root mean square velocity (RMS) is C; then at temperature T and pressure 3P the RMS is
A. Unchanged
B. 3C
C. C/3
D. $C^3$
Answer : A

3. If the tetrahedral sites in ccp arrangement of negative ions (Y) were half filled with cation (X), the empirical formula of the compound would be
A. $X_{2}Y$
B. XY
C. $X{Y}_2$
D. $X_2{Y}_3$
Answer : B

4. The vapour density of a gas is 11.2. The volume occupied by 2.4 g of the gas at S.T.P wil be
A. 2.4 litres
B. 3.6 litres
C. 2.24 litres
D. 11.2 liters
Answer : D

5. How many nearest neighbours are there in an octahedral hole of a close packed structure
A. 4
B. 6
C. 8
D. 12
Answer : B

6. The average kinetic energy of the molecule of $S{O}_2$ (moL wt. = 64) at 27°C is E. Then the average kinetic energy of $C{O}_2$ at 27°C is
A. $\frac{E\times 64}{44}$
B. $\frac{E\times 44}{64}$
C. E
D. 22E
Answer : C

7. The critical temperature of a substance is defined as
A. the temperature above which the substance decomposes
B. the temperature above which the substance can exist only as a gas
C. melting point of the substance
D. boiling point of the substanc
Answer : B

8. Kinetic theory of gases postulates :
A. The molecules in a gas are in stationary state
B. The molecules in a gas exert appreciable attraction on each other
C. The molecules move in a random motion with widely different velocities
D. The molecules in a gas collide against each other as well as the wall of the container, but do not change their direction of motion
Answer : C

9. The number of molecules is 4.25 g of ammonia are approximately
A. 3.5 x ${}^{{10}^{23}}$
B. 2.5 x ${}^{{10}^{23}}$
C. 1.5 x ${}^{{10}^{23}}$
D. 0.5 x ${}^{{10}^{23}}$
Answer : D

10. The number of molecules in 32 gms of oxygen in
A. 6.02 x ${}^{{10}^{10}}$
B. 3.2 x ${}^{{10}^{23}}$
C. 6.02 x ${}^{{10}^{22}}$
D. 32 x ${}^{{10}^{10}}$
Answer : A

11. The vol. of 20 gms of nitrogen at N.T.P.
A. 16 litres
B. 36 litres
C. 8 litre
D. 32 litres
Answer : C

12. The vapour density of gas A is four times that of gas B. If the molecular weight of gas B is M, then the molecular weight of gas A is
A. 2M
B. 4M
C. 8M
D. M/4
Answer : B

13. Indicate the most viscous liquid of the following
A. propanol-2
B. 1.2, ethandiol
C. 1.2,3 propentriol
D. ethanol
Answer : C

14. 20 litres of hydrogen gas weighs about
A. 1.8 g
B. 3.6 g
C. 224 g
D. 12.2 g
Answer : A

15. The number of molecules in 4.25 gm of ammonia are approximately
A. $0.5\times {10}^{23}$
B. $1.5\times {10}^{23}$
C. $2.5\times {10}^{23}$
D. $3.5\times {10}^{23}$
Answer : B

16. A balloon filled with ethane is pricked up with sharp point and quickly plunged into a tank of hydrogen at the same pressure. After some time balloon will
A. be enlarged
B. be collapse
C. remain unchanged in size
D. have half its volume of the gas
Answer : A

17. An element has atomic weight 24 and equivalent weight 11.9. Its valency is
A. 1
B. 2
C. 3
D. 4
Answer : B

18. Which of the following should be most viscous?
A. $C{H}_{3}OH$
B. $C{H}_{3}C{H}_{2}OH$
C. $C{H}_{3}OC{H}_3$
D. $HOC{H}_{2}C{H}_{2}OH$
Answer : D

19. The Van der Waal's equation explains the behaviour of
A. ideal gases
B. real gases
C. vapours
D. non-real gases
Answer : B

20. All gases tend to show ideal behaviour
A. at low temperature and low pressure
B. at high temperature and high pressure
C. at high temperature and low pressure
D. at low temperature and high pressure
Answer : C

21. The number of molecules of $C{O}_2$ present in 44 gms. of $C{O}_2$ is
A. 6 x ${}^{{10}^{23}}$ approx
B. ${10}^{30}$ approx
C. 3 x ${}^{{10}^{10}}$ approx
D. 12 x ${ }^{{10}^{23}}$ approx
Answer : B

22. The limiting radii ratio for the tetrahedral geometry is
A. 0.155
B. 0.444
C. 0.732
D. 0.225
Answer : D

23. What will be the mass of 6.03 x ${}^{{10}^{23}}$ molecules of carbon monoxide ?
A. 18.00
B. 28.01
C. 56.02
D. 14.05
Answer : B

24. At 303 K ethanol has a vapour pressure of about 0.118 atm., acetic acid has the vapour pressure of about 0.039 atm., and ethyl iodide has a vapour pressure of about 0.263 atm. Which of the following represents the correct order of increasing normal boiling point ?
A. $C{H}_{3}COOH<C_2{H}_{5}OH<C_2{H}_{5}I$
B. $C_2{H}_{5}I<C{H}_{3}COOH<C_2{H}_{5}OH$
C. $C_2{H}_{5}I<C_2{H}_{5}OH<C{H}_{3}COOH$
D. $C_2{H}_{5}OH<C_2{H}_{5}I<C{H}_{3}COOH$
Answer : C

25. A chalk box exhibits
A. cubic geometry
B. monoclinic geometry
C. orthorhombic geometry
D. tetragonal
Answer : A

26. When there is more deviation in the behaviour of a gas from ideal gas equation PV = nRT
A. at high temperature and low pressure
B. at low temperature and high pressure
C. at high temperature and high pressure
D. at low temperature and low pressure
Answer : B

27. In which one of the following does diffusion occur most rapidly?
A. Solid
B. Liquid
C. Gases
D. Gels
Answer : C

28. The ionic radii of $R{b}^{+}$ and $B{r}^{-}$ ions are 1.47 $\stackrel{°}{A}$ and 1.95 $\stackrel{°}{A}$, respectively. The most probable type of geometry exhibited by RbBr on the radius ratio rule is
A. NaCl type
B. CsCl type
C. Zinc blende structure
D. Wurtzite structure
Answer : B

29. The coordination number of each sphere in hcp arrangement is
A. 12
B. 8
C. 6
D. 4
Answer : A

30. The vapour density of pure ozone would be
A. 32
B. 8
C. 12
D. 24
Answer : B

31. A liquid of density 1.742 g $c{m}^{-3}$ is observed to show a capillary rise of 73 mm in a tube of radius 0.65 mm. Then the surface tension of the liquid is
A. 4.1 x ${}^{{10}^{-2}}$ dynes $c{m}^{-1}$
B. 4.1 x ${10}^3$ dynes $c{m}^{-1}$
C. 7.1 x ${10}^{-3}$ dynes $c{m}^{-1}$
D. None of these
Answer : B

32. 6.If the reactants and products both are in gaseous phase they bear a simple ratio in their
A. volumes
B. molecules
C. atoms
D. temperature
Answer : A

33. 1.The correct relationship representing the volume occupied by 44 gm of $C{O}_2$ and 64 gm of $S{O}_2$ at constant temperahire and pressure:
A. V($C{O}_{2 }$) > V($S{O}_2$)
B. V($C{O}_{2 }$) = V($S{O}_2$)
C. V($S{O}_2$) > V($C{O}_{2 }$)
D. cannot be predicted
Answer : B

34. Absolute zero is the temperature at which
A. water freezes
B. all gases become liquid
C. all substances are solid
D. molecular motion ceases
Answer : D

35. The number of atoms in 0.004 gm of magnesium is close to
A. 36x ${ }^{{10}^5}$
B. ${ }^{{10}^{20}}$
C. 5 x ${ }^{{10}^{20}}$
D. 6.02 x ${}^{{10}^{23}}$
Answer : B

36. The pressure of the ideal gas is less than the real gas because of the
A. increase in the number of collisions
B. volume occupied by the molecules
C. inter-molecular attraction
D. finite size of molecules
Answer : C

37. 22.4 litres of $S{O}_2$ at 27.3°C and 1 atmosphere pressure shall weigh
A. 32 g
B. 16 g
C. 44.8 g
D. 48.5 g
Answer : D

38. In a face centred cubic arrangement of ions, the coordination number of ions is
A. 6
B. 8
C. 12
D. 4
Answer : C

39. What types of forces are present in molecular solids?
A. electrovalent bonds
B. hydrogen bonds
C. metallic bonds
D. Van der Waal's forces
Answer : D

40. 22.4 litre of any gas at N.T.P. will contain
A. One gram equivalent
B. One gram atomic weight
C. One gram atom
D. One gram molecule
Answer : D

41. In a close packed arrangement of N spheres, the number of octahedral holes are
A. N
B. 2N
C. 4N
D. 8N
Answer : A

42. At what temperature, the root mean square velocity of oxygen molecules is equal to that of $S{O}_2$ at 27°C?
A. 150°C
B. 150°K
C. 27°C
D. None of these
Answer : B

43. Match box has the symmetry of which of the following systems?
A. Cubic
B. Orthorhombic
C. Tetragonal
D. Monoclinic
Answer : A

44. Equal weights of methane and hydrogen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by methane is
A. 1/2
B. 1/3
C. 1/9
D. 8/9
Answer : C

45. Four 1 litre flasks are separately filled with hydrogen, helium, oxygen and ozone gases at the same temperature and pressure. The ratio of total number of atoms of these gases present in the different flasks would be
A. 1:1:1:1
B. 1:2:2:3
C. 2:1:2:3
D. 3:2:2:1
Answer : C

46. In a dose packed arrangement of N spheres, the number of tetrahedral holes are
A. N
B. 2N
C. N/2
D. $N_2$
Answer : B

47. Which of the following is an amorphous solid?
A. NaCl
B. $Ca{F}_2$
C. Diamond
D. Glass
Answer : D

48. Which of the following methods is used to determine the atomic weight?
A. Victor Meyer's method
B. Dumas' method
C. Cannizaro's method
D. None of these
Answer : C

49. Of the following properties, the magnitude of one must always increase with temperature. The property is
A. vapour pressure
B. density
C. $∆H_{vap}$
D. surface tension
Answer : A

50. The vol. of 20 gm. of hydrogen at N.T.P. is
A. 22.4 litres
B. 112 litres
C. 12 litres
D. 224 litres
Answer : A