General Science (Chemistry) Practice Questions

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 law 
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? – 610. Sodium carbonate crystals lose water molecules. What is this property called? – Efflorescence 

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? – Poison 
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? – Pt 
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? – Increases 
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 Entropy 
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 reactions 
82. Which is the element that has the highest first ionization potential? – Nitrogen 
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? – Non-metals 
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? – Barium 
93. Which block of elements is mostly metals with high B.P., M.P. values? – d-block 
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, Cl 
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