Problem 25
The density of air is \(0.001293 \mathrm{~g} / \mathrm{cc}\) at STP. Its vapour density is (a) \(0.001293\) (b) \(8.2786\) (c) \(14.48\) (d) \(6.2706\)
Problem 26
At \(27^{\circ} \mathrm{C}\), a closed vessel contains a mixture of equal weights of helium (mol. wt \(=4\) ), methane (mol. wt \(=16\) ) and sulphur dioxide (mol. wt \(=64\) ). The pressure exerted by the mixture is \(210 \mathrm{~mm}\). If the partial pressures of helium, methane and sulphur dioxide are \(\mathrm{P}_{1}, \mathrm{P}_{2}\) and \(\mathrm{P}_{3}\) respectively, which one of the following is correct? (a) \(\mathrm{P}_{3}>\mathrm{P}_{2}>\mathrm{P}_{1}\) (b) \(\mathrm{P}_{1}>\mathrm{P}_{2}>\mathrm{P}_{3}\) (c) \(\mathrm{P}_{1}>\mathrm{P}_{3}>\mathrm{P}_{2}\) (d) \(\mathrm{P}_{2}>\mathrm{P}_{3}>\mathrm{P}_{1}\)
Problem 27
4 grams of an ideal gas occupies \(5.6035\) litres of volume at \(546 \mathrm{~K}\) and 2 atm pressure. What is its molecular weight? (a) 4 (b) 16 (c) 32 (d) 64
Problem 28
The kinetic energy of 4 moles of nitrogen gas at \(127^{\circ} \mathrm{C}\) is ....... Kcals. \(\left(\mathrm{R}=2 \mathrm{cal} \mathrm{mol}^{-1} \mathrm{~K}^{-1}\right)\) (a) 4400 (b) 3200 (c) 4800 (d) 1524
Problem 29
If a gas contains only three molecules that move with velocities of \(100,200,500 \mathrm{~ms}^{-1}\), what is the \(\mathrm{rms}\) velocity of the gas is \(\mathrm{ms}^{-1 ?}\) (a) \(100 \sqrt{8 / 3}\) (b) \(100 \sqrt{30}\) (c) \(100 \vee 0\) (d) \(800 / 3\)
Problem 30
A gaseous mixture contains \(56 \mathrm{~g}\) of \(\mathrm{N}_{2}, 44 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) and \(16 \mathrm{~g}\) of \(\mathrm{CH}_{4}\). The total pressure of mixture is \(720 \mathrm{~mm}\) of \(\mathrm{Hg}\). The partial pressure of methane is (a) \(75 \mathrm{~mm}\) (b) \(160 \mathrm{~mm}\) (c) \(180 \mathrm{~mm}\) (d) \(215 \mathrm{~mm}\)
Problem 31
At \(25^{\circ} \mathrm{C}\) and \(730 \mathrm{~mm}\) pressure, \(380 \mathrm{~mL}\) of dry oxygen was collected. If the temperature is constant, what volume will the oxygen occupy at \(760 \mathrm{~mm}\) pressure? (a) \(365 \mathrm{~mL}\) (b) \(2 \mathrm{~mL}\) (c) \(10 \mathrm{~mL}\) (d) \(20 \mathrm{~mL}\)
Problem 32
The density of an ideal gas is \(0.03 \mathrm{~g} \mathrm{~cm}^{-3}\), Its pressure is \(106 \mathrm{~g} \mathrm{~cm}^{-1} \mathrm{sec}^{-2}\). What is its \(\mathrm{ms}\) velocity (in \(\left.\mathrm{cm} \sec ^{-1}\right)\) ? (a) \(10^{3}\) (b) \(3 \times 10^{4}\) (c) \(10^{2}\) (d) \(10^{4}\)
Problem 33
At a certain pressure, volume of a gas at \(27^{\circ} \mathrm{C}\) is 20 litre. If the pressure and temperature are doubled, its volume will be (a) 20 litre (b) 40 litre (c) \(8.2\) litre (d) \(10.9\) litre
Problem 34
\(\mathrm{A}\) and \(\mathrm{B}\) are ideal gases. The molecular weights of \(\mathrm{A}\) and \(\mathrm{B}\) are in the ratio of \(1: 4\). The pressure of a gas mixture containing equal weights of \(\mathrm{A}\) and \(\mathrm{B}\) is \(\mathrm{P}\) atm. What is the partial pressure (in atm) of B in the mixture? (a) \(\mathrm{P} / 5\) (b) \(\mathrm{P} / 2\) (c) \(\mathrm{P} / 2.5\) (d) \(3 \mathrm{P} / 4\)
