MDCAT Chemistry Online Test With Answers

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MDCAT Chemistry Online Test

Sr. # Questions Answers Choice
1 The number of NaCI molecules in unit cell of its crystal is 2 4 6 8
2 The ratio of close packed atoms to tetrahedral holes in cubic close packing is 1 : 1 1 : 2 1 : 3 2 : 1
3 Potassium crystallizes with a Orthogonal lattice Cubic lattice Triclinic Ortho rhombic lattice
4 How many kinds of space lattices are possible in a crystal? 23 7 230 14
5 In a crystal a ≠ b ≠ c,a = y 90° and β ≠ 90° it is Monoclinic Rhombic Trigonal Tetragonal
6 Bragg's law is given by equation n λ = 2 θ sin θ nλ = 2 d sin θ 2nλ = d sin θ n λ= 1/2 d sin θ
7 In crystal structure of sodium chloride,the arrangement of CI- ions is Fcc Both fcc and bcc Bcc None of these
8 Crystal can be classified in to ......basic crystal habits 7 4 14 3
9 Ionic solids with defects,contain Equal number of cation and anion vacancies Interstitial anions and anion vacanies Cation vacancies only Cation vacancies and interstitial cations
10 Which of the following is an example of body centred cube? Magnesium Zinc Copper Sodium
11 The pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at higher temperature turbidity completely disapp-ears.The behaviour is a characteristic of substance forming Allotropic crystal Liquid crystals Isomeric crystals Isomorphous crystals
12 The factor responsible for lower mercury level in a capillary tube is High density Surface tension Liquid state Metallic Colour
13 Triple point of water is 273 K 373 K 203 K 193 K
14 4.4 g of CO2 contains how many litres of CO2 at STP? 2.4 litre 2.24 litre 44 litre 22.4 litre
15 What is the pressure of 2 mole of NH3 at 27°C when its volume is 5 lit.in Van der Waals equation?(a = 0,17,b = 0.03711) 10.33 atm 9.333 atm 9.74 atm 9.2 atm
16 The ratio of most probable velocity to that of average velocity is π/2 2/π √π/2
17 Hydrogen diffuses six times faster than gas A.The molar mass gas of gas A is 72 6 24 36
18 To which of the following mixtures Dalton's law of partial pressures is not applicable? CO and CO<sub>2</sub> CO<sub>2</sub> and N<sub>2</sub> CH<sub>4</sub> and C<sub>2</sub>H<sub>6</sub> HCI and NH<sub>3</sub>
19 Which of the following contains maximum of number of molecules? 100 cc of CO<sub>2</sub> at STP 150 cc of N<sub>2 </sub>at STP 50 cc of SO<sub>2</sub> at STP 200 cc of NH<sub>3</sub> at STP
20 In van der Waal's equation of state of the gas law,the constant 'b' is measure of Intermolecular repulsions Intermolecular collisions per unit volume Volume occupied by the molecules Intermolecular attraction
21 Molar volume of CO2 is maximum at NTP 0°C and 2.0 atm 127°C and 1 atm 273°C and 2.0 atm
22 The rate of diffusion of a gas is proportional to P /√d √p/d P/d √ P/d
23 The kinetic energy of 4 moles of nitrogen gas at 127°C is? cals.(R = 2 cal mol-1 K-1) 4400 3200 4800 1524
24 Which of the following statement is not true? The pressure of a gas is due to collision of the gas molecules with the walls of the container. The molecular velocity of any gas is proportional to the square root of the absolute temperature. The rate of diffusion of a gas is directly proportional to the density of the gas at constant pressure. Kinetic energy of an ideal gas is directly proportional to the absolute temperature.
25 Absolute temperature is the temperature at which All molecular motion ceases volume becomes zero Mass becomes zero None of these
26 Kinetic energy of one mole of an ideal gas at 300 K in kJ is 34.8 3.48 3.74 348
27 According to the kinetic theory of gases,in an ideal gas,between two successive collisions a gas molecule travels Ina circular path In a wavy path In a straight line path With an accelerated velocity
28 What is distilled first? Liquid CO<sub>2</sub> Liquid N<sub>2</sub> Liquid O<sub>2</sub> Liquid H<sub>2</sub>
29 When the temperature is raised, the viscosity of the liquid decreases.This is because of Decreased volume of the solution Increase in temperature increases the average kinetic energy of molecules which overcome the attractive force between them Decreased covalent and hydrogen bond forces Increased attraction between the moelcules
30 If the four tubes of a car are filled to the same pressure with N2, O2, H2 and helium separately,then which one will be filled first. N<sub>2</sub> O<sub>2</sub> H<sub>2</sub> He
31 Air at sea level is dense.This is a practical application of Boyle's law Charle's law Avogadro's law Dalton's law
32 Equal volumes of gases at the same temperature and pressure contain equal number of particles.This statement is direct consequence of Perfect gas law Partial law of volumes Charle's law Ideal gas equation
33 For an ideal gas,number of moles per litre in terms of its pressure P,gas constant R and temperature T is PT/R PRT P/RT RT/P
34 The temperature below which a gas does not exist is called its Inversion temperature Critical temperature Neutral temperature Curie point
35 The relationship which describes the variation of vapour pressure with temperature is called Hess's law Arrhenius equation Kirchhoff's law Clausius-Clapeyron equation
36 At STP,a container has 1 mole of Ar,2 moles of CO2,3 moles of O2 and 4 moles of N2.Without changing the total pressure if one mole of O2 is removed,the partial pressure of O2 Is changed by about 26% Is halved Is unchanged Change by 33%
37 Two moles of an ideal gas at 1 atm are compressed to 2 atm at 273 K.The enthalpy change for the process is 2 litre atm 1 litre atm Zero 3 litre atm
38 The volume of 2.8 g of carbon monoxide at 27°C and 0.821 atm pressure is (R = 0.0821 lit.atm.Mol-1 K-1) 30 L 3 L 0.3 L 1.5 L
39 If the volume of 2 moles of an ideal gas at 540 K is 44.8 litre then its pressure will be 1 atmosphere 2 atmosphere 3 atmosphere 4 atmosphere
40 The compressibility factor of an ideal gas is 0 1 2 4
41 The average kinetic energy of an ideal gas per molecule is SI units at 25°C will be 6.17 x 10<sup>-21</sup> KJ 6.17 x 10<sup>-21</sup> J 6.17 x 10<sup>-20</sup> J 7.16 x 10<sup>-20</sup> J
42 The densities of two gases are in the ratio of 1 : 16.The ration of their rates of diffusion is 16 : 1 4 : 1 1 : 4 1 : 16
43 An ideal gas obeying kinetic gas equation can be liquefied if Its temperature is more than critical temperature Its pressure is more than critical pressure Its pressure is more than critical pressure but temperature is less than critical temperature It cannot be liquefied at any value of P and T
44 Which of the following statements is false? Avogadro number = 6.02 x 10<sup>21</sup> The relationship between average velocity (v) and root mean square velocity (u) is v = 0.9213 u The mean kinetic energy of an ideal gas is independent of the pressure of the gas The root mean square velocity of the gas can be calculated by the formula (3RT/M)<sup>1/2</sup>
45 The temperature of the gas is raised from 27°C to 927°C the root mean square velocity is √927/27 times the earlier value Same as before Halved Doubled
46 The number of moles of H2 in 0.224 L of hydrogen gas at STP (273 K, 1 atm) assuming ideal gas behaviour is 1 0.1 0.01 0.001
47 The density of methane at 2.0 atmosphere pressure at 27°C is 0.13 gL<sup>-1</sup> 0.26 gL<sup>-1</sup> 1.30 gL<sup>-1</sup> 26.0 gL<sup>-1</sup>
48 If rate of diffusion of A is 5 times that of B,what will be the density ratio of A and B? 1/25 1/5 25 5
49 An ideal gas cannot be liquefied because Its critical temperature is always above 0°C Its molecules are relatively small in size It solidifies before becoming a liquid Forces operative between its molecules are negligible.
50 The correct value of the gas constant R is close to 0.082 litre-atm K<sup>-1</sup> mol<sup>-1</sup> 0.082 litre-atm<sup>-1</sup> K mol 0.082 litre-atm K 0.082 litre-atm<sup>-1</sup> K mol<sup>-1</sup>
51 A real gas most closely approaches the behaviour of an ideal gas at 15 atm. and 200 K 1 atm. and 273 K 0.5 atm.and 500 K 15 tm, and 500 K
52 There is more deviation in the behaviour of a gas from the ideal gas equation PV = nRT At high temperature and low pressure At low temperature and high pressure At high temperature and high pressure At low temperature and low pressure
53 In the equation PV = nRT which one cannot be numerically equal to R 8.31 x 10<sup>7</sup> erg<sup>7</sup> K<sup>-1</sup> mol<sup>-1</sup> 8.31 x 10<sup>7</sup> dynes Cm K<sup>-1</sup> mol<sup>-1</sup> 8.31 JK<sup>-1</sup> mol<sup>-1</sup> 8.31 L atm K<sup>-1</sup> mol<sup>-1</sup>
54 According to kinetic theory of gases there are Intermolecular attractions Molecules which have considerable volume No intermolecular forces of attraction The velocity of molecules decreases for each collision.
55 The vapour density of a gas is 11.2.The volume occupied by 11.2 g of this gas at N.T.P is 22.4 litres 11.2 litres 1 litre 2.24 litres
56 Wt. of 112 ml of oxygen at NTP on liquifaction would be 0.32 g 0.64 g 0.16 g 0.96 g
57 The weight of 11.2 liters of CO2 at S.T.P would be 88 g 44 g 32 g 22 g
58 The number of atoms in 0.004 g of magnesium is close to 24 2 x 10<sup>20</sup> 10<sup>20</sup> 6.02 x 10<sup>23</sup>
59 One mole of a gas refers to The number of molecules in one litre of gas The number of molecules in one gram of gas The number of molecules contained in 12 grams of <sup>12</sup>C isotope The number of molecules in 22.4 liters of a gas at S.T.P.
60 The relative rate of diffusion of a gas (molecular weight = 128) as compared to oxygen is 2 times 1/4 1/8 1/2
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