General science 100 Important Questions and Answers Part Five

1. What is the name of the scientist who stated that matter
can be converted into energy? – Einstein
2. The isotopes of chlorine with mass number 35 and 37 exist in which ratio? –
3 : 1
3. A gas is found to have the formula (CO)n. Its vapour density is 70. What
must the value of n be? – 5
4. Which law directly explains the law of conservation of mass? – Avogadro’s
5. To whom the credit for the discovery of transuranic element goes? – Seaborg
6. How many moles are there is 140 g of Si (atomic mass of silicon is 28)? – 5
7. Which substance does not have a melting point? – Glass
8. By which a mixture of sand and naphthalene can be separated? – sublimation
9. An element X forms an oxide X03. What is the valency of X? – 6
10. Sodium carbonate crystals lose water molecules. What is this property
called? – Efflorescence
11. By whom was the law of constant proportions enunciated? – Proust
12. What is the number of unpaired electrons in carbon atom? – 2
13. In an atom the order of filling up of the orbitals is governed by which
principle? – Aufbau principle
14. Regarding the atom of a chemical element, magnetic quantum number refers? –
15. What are the atoms of the elements having same mass number but different
atomic number called? – isobars
16. Rutherford’s scattering experiment related to the size of which thing? –
17. By whom was the absolute value of charge on electron determined? – R.A.
18. Which property of the elements is a whole number? – Atomic number
19. Discovery of the nucleus of an atom was due to the experiment carried out
by which person? – Rutherford
20. What are the atoms of the elements which have same number of neutrons
called? – Isotones
21. Whose experiment proved that the speed of light was always the same? –
Michelson and Morley
22. Which element has two electrons in the K-shell only? – Helium
23. What is Electromagnetic radiation with maximum wavelength? – Radio waves
24. Which nuclear particles responsible for holding all nucleons together? –
25. In which process, a nucleus spontaneously breaks down by emitting
radiation? – Radioactive decay
26. In atomic reactors, graphite is used as which name? – Moderator
27. Why is Cobalt-60 commonly used in radiation therapy? –Because it emits
gamma rays
28. A radioactive substance has a half life of four months. Three-fourth of the
substance would decay in howmany months? – 8 months
29. What is a bond formed by the transfer of electrons between atoms of the
elements called? – ionic bond
30. What is a bond formed by sharing of electrons between atoms of the elements
called? – covalent bond
31. What is the maximum number of hydrogen bonds in a H2O molecule? – 4
32. Select the compound in which chlorine shows oxidation state + 7? – HClO4
33. What is the oxidation of two Cl atoms in bleaching powder Ca(OCl) Cl? –
34. What is the Oxidation state of Mn in acidic KMnO4 change from? – +7 to +2
35. Why is Molten NaCl good conductor of electricity? – Free ions
36. What is the common oxidation state of alkali metals in the combined state?
– +1
37. What is the oxidation number and covalency-of sulphur in S8? – 0, 2
38. Starch iodide paper is used to test for the presence of which agent? –
Oxidising agent
39. The pH of water at 25° C is 7. When it is heated to 100°C, what will the pH
of water? – increases
40. When Metal carbonate reacts with dilute acids, what does it forms? – CO2
41. The element common to all the acids is known as which name? – Hydrogen
42. What is the sum of pH and pOH in aqueous solution at 25°C? – 14
43. By what factor is a solution with pH = 2 more acidic than one with pH = 6 ?
– 104

44. Red litmus paper is changed into blue in solution of which thing? – Base
45. What is formed by dissolution of base or acid in water? – Exothermic
46. Blue litmus paper is converted into red in solution of which thing? – acid
47. According to Arrhenius theory of an acid and base, an acid is a substance
that gives which ions in water? – H+ ions
48. What is the negative logarithmic value of hydrogen on called? – pH
49. What are the physical state of dispersion medium of a cloud ? – Gas
50. Vander Wall’s equation explains the behaviour of which gases? – real gases
51. In general gas equation, pV= nRT, V is the volume of which gas? – n mole of
a gas
52. What is the ratio of rate of diffusion of oxygen and hydrogen? – 1 : 4
53. Absolute zero is the temperature where all gases are expected to have
howmuch volume? – Zero volume
54. 4.4 g of CO2 contains how many litre of CO2 at STP? – 2.24 litre
55. Glucose or fructose is converted into C2H5OH in the presence of which
thing? – zymase
56. Which type of materials act as effective catalysis? – Transition metals
57. What is the substance which decreases the rate of a chemical reaction? –
58. TEL minimise the knocking effect when mixed with petrol, how does it act? –
As negative catalyst
59. Which is the catalyst used in the manufacture of sulphuric acid by contact
process? – V2O5
60. Which catalyst is sensitive to temperature changes? – Enzyme
61. Which is the temperature at which the catalytic activity of the catayist is
maximum? – Optimum temperature
62. Alcoholic fermentation is brought about the action of which thing? – Yeast
63. Which is catalyst used in the Deacon’s process for the manufacture of
chlorine? – CuCl2
64. In the Ostwald’s process for manufacture of HNO3, which catalyst is used? –
65. Which gas has maximum colorific value? – Oil gas
66. When ammonium chloride is dissolved in water, the solution becomes cold.
Whiat is change? – Endothermic
67. When ice melts into water, which type of change occurs in entropy? –
68. In which type of coal percentage of carbon is the highest? – Anthracite
69. What is the mixture of carbon monoxide and nitrogen called? – Producer gas
70. What is the mixture of carbon monoxide and hydrogen called? – Water gas
71. Which law of thermodynamics introduces the concept of entropy? – Second law
72. For which element, the standard enthalpy is not zero? – C (Diamond)
73. Which fuel causes minimum environmental pollution? – Hydrogen
74. Which gas has the highest fuel value? – Hydrogen
75. The compound with negative heat of formation is known as which name? –
Exothermic compound
76. Which hydrocarbon is mainly present in gobar gas? – Methane
77. What happens when the door of a refrigerator is kept open? – Room heated
78. What does the second law of thermodynamics introduced? – The concept of
79. What is an extensive property of the system? – Volume
80. A gas expands isothermally and reversible. How much work is done by the
gas? – Maximum
81. About which is the information not conveyed by thermodynamics? – Rates of
82. Which is the element that has the highest first ionization potential? –
83. What has the highest ionization potential? – Ne
84. Which of the following among alkali metals is most reactive? – Cs
85. Which is the element having lowest melting point in periodic table? – He
86. Which are the elements on the right side of the periodic table? –
87. Which transition metal is in liquid state? – Mercury
88. Which electronic configurations exhibits metallic character? – 2, 8, 2
89. Which element has the lowest electron affinity? – Argon
90. By whom was the calculation of electronegativities first done? – Pauling
91. Which element does not exist in liquid state at room temperature ? – Na
92. What is the most electropositive amongst the alkaline earth metals? –
93. Which block of elements is mostly metals with high B.P., M.P. values? –
94. Which are the vertical lines in modern periodic table called? – Group
95. What is horizontal line in modern periodic table called? – Period
96. In a period, the elements are arranged in which order? – Increasing charges
in the nucleus
97. Which noble gas does not have octet of electrons in its outer shell? – He
98. Which pair of elements is in the same period of the periodic table? – Na,
99. Why is the electron affinity of chlorine highest than that of fluorine? –
Smaller nuclear charge
100. What is the Electron affinity of noble gases? – Almost zero

General science 100 Important Questions and Answers Part Four

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