States of Matter PYQs Set 5 (PDF)

Set 5 of 8 · Questions 121-150 of 228

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher · Previous Year Questions JEE Main Chemistry · States of Matter · Set 5 (Q121-150)
Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.
121. $A 100 L cylinder containing H_{2} exerted a pressure of 4 atm at 300 K . It was accidentally opened and some H_{2} was escaped. When it was closed, it exerted a pressure of 3 atm at 300 K . The number of moles of H_{2} remaining in the cylinder is equal to(Assume H_{2} as an ideal gas; R = gas constant)$ (1) $1 2 R$ (2) $R$ (3) $\frac{1}{R}$ (4) $2 R$ 122. $The temperature at which 4 moles of a gas occupy 5 dm^{3} volume at 3.32 bar pressure is$ (1) $50 K$ (2) $50^{\circ} C$ (3) $27^{\circ} C$ (4) $100 K$ 123. $What is the density of one mole of He (molar mass = 4 g (mol^{- 1}) at 300 K and a pressure of 0.82 atm ? (R = 0.082 L atm mol^{- 1} K^{- 1})$ (1) $1.33 \times 10^{- 2} g mL^{- 1}$ (2) $1.33 \times 10^{- 2} g L^{- 1}$ (3) $1.33 \times 10^{- 1} g L^{- 1}$ (4) $1.33 \times 10^{- 1} g mL^{- 1}$ 124. $One mole of an ideal gas occupies 12 L at 297^{\circ} C . What is the pressure of the gas?$ (1) $207 kPa$ (2) $395 kPa$ (3) $395 Pa$ (4) $207 Pa$ 125. $Find the temperature in degree celsius if volume and pressure of 2 mole ideal gas is 20 dm^{3} and 4.926 atmosphere respectively. (R = 0.0821 dm^{3} atm K^{- 1} mol^{- 1})$ (1) $273$ (2) $327$ (3) $600$ (4) $453$ 126. $At 27^{\circ} C in a 10 L flask 4.0 g of an ideal gaseous mixture containing. He (molar mass 4.0 g mol^{- 1}) and Ne (molar mass 20 g mol^{- 1}) has a pressure of 1.23 atm . What is the mass % of neon? (R = 0.082 L atm K^{- 1} mol^{- 1})$ (1) $25.2$ (2) $62.5$ (3) $84.2$ (4) $74.2$ 127. $Which of the following gases has the highest value of RMS velocity at 298 K ?$ (1) $CH_{4}$ (2) $CO$ (3) $Cl_{2}$ (4) $CO_{2}$ 128. $At a given temperature T, gases Ne, Ar, Xe and Kr are found to deviate from ideal gas behavior. Their equation of state is given as P = \frac{RT}{V - b} at T. Here, b is the van der Waals constant. Which gas will exhibit steepest increase in the plot of Z (compression factor) vs P ?$ (1) $Xe$ (2) $Kr$ (3) $Ne$ (4) $Ar$ 129. $A neon-dioxygen mixture contains 64 g_{2} and 160 g Ne. If the total pressure is 25 bar, calculate the partial pressure of dioxygen.$ (1) $5 bar$ (2) $7.5 bar$ (3) $10 bar$ (4) $20 bar$ 130. $The compressibility factor (z) is lower for NH_{3} and CO_{2} gases than that of N_{2} gas, because$ (1) $van der Waals constants 'a' of CO_{2} and NH_{3} are greater than that of N_{2}$ (2) $van der Waals constants 'a' of CO_{2} and NH_{3} are less than that of N_{2}$ (3) $'a' (NH_{3}) > a'^{2} (N_{2}) but 'a' (CO_{2}) <'a' (N_{2})$ (4) $'a' (NH_{3}) <'a' N2 but 'a' (CO_{2}) >'a' N2$ 131. $A balloon filled with ethyne is pricked with a sharp point and quickly dropped in a tank of H_{2} gas under identical conditions. After a while the balloon will :$ (1) $Shrink$ (2) $Enlarge$ (3) $Completely collapse$ (4) $Remain unchanged in size$ 132. $Which of the following is not the correct set of pressure and volume at constant temperature and constant moles of gas ? P V$ (1) $1 atm 200 ml$ (2) $760 mm 0.2 L$ (3) $0.5 atm 100 L$ (4) $2 atm 100 mL$ 133. $At 0^{\circ} C a gas occupies 22.4 liters. What is the temperature in Kelvin to reach the volume of 224 liters?$ (1) $546 K$ (2) $273 K$ (3) $2730 K$ (4) $5460 K$ 134. $At a given temperature, the density of an ideal gas is proportional to (P = pressure of ideal gas)$ (1) $\frac{1}{P}$ (2) $P$ (3) $P^{2}$ (4) $P$ 135. $Helium molecule is two times heavier than hydrogen molecule at 298 K . According to kinetic theory, the average kinetic energy of helium at 298 K is$ (1) $two times higher than a hydrogen molecule$ (2) $four times higher than a hydrogen molecule$ (3) $same as that of a hydrogen molecule$ (4) $half of a hydrogen molecule$ 136. $At 300 K, the following graph is obtained for one mole of an ideal gas. If its pressure is 10 atm, then its volume (in L) will be$ (1) $0.11$ (2) $1.1$ (3) $2.0$ (4) $4.0$ 137. $Which one of the following statements is not true about the effect of an increase in temperature on the distribution of molecular speeds in a gas ?$ (1) $The area under the distribution curve remains the same as under the lower temperature$ (2) $The distribution becomes broader$ (3) $The fraction of the molecules with the most probable speed increases$ (4) $The most probable speed increases$ 138. $Following represent the Maxwell distribution curve for an ideal gas at two temperature T_{1} and T_{2} . Which of the following option(s) are true ?$ (1) $Total area under the two curves is independent of moles of gas$ (2) $U_{m p s} decreases as temperature decreases$ (3) $T_{1} > T_{2} and hence higher the temperature, sharper the curve$ (4) $The fraction of molecules having speed = decreases as temperature increases$ 139. $At what temperature root mean square speed of N_{2} gas is equal to that of propane gas at S.T.P. conditions.$ (1) $173.7°C$ (2) $173.7 K$ (3) $S.T.P.$ (4) $- 40°C$ 140. $For one mole of a van der Waals gas when b = 0 and T = 300 K, the PV vs.1/V plot is shown below. The value of the vanderWaals constant a (atm. l i t e r^{2} m o l^{-2}) :$ (1) $1.0$ (2) $4.5$ (3) $1.5$ (4) $3.0$ 141. $For 1 mol of gas, the plot of pV vs p is shown below, p is the pressure and V is the volume of the gas. What is the value of compressibility factor at point A?$ (1) $1 - \frac{a}{R T V}$ (2) $1 + \frac{b}{V}$ (3) $1 - \frac{b}{V}$ (4) $1 + \frac{a}{R T V}$ 142. $A quantity of gas is collected in a graduated tube over the mercury. The volume of gas at 18 ºC is 50 ml and the level of mercury in the tube is 100 mm above the outside mercury level. The barometer reads 750 torr. Hence, volume at S.T.P. is approximately :$ (1) $22 ml$ (2) $40 ml$ (3) $20 ml$ (4) $44 ml$ 143. $The combination of plots which does not represent isothermal expansion of an ideal gas :$ (1) $(B) and (D)$ (2) $(A) and (C)$ (3) $(B) and (C)$ (4) $(A) and (D)$ 144. $A gaseous mixture of three gases A, B and C has a pressure of 10 atm. The total number of moles of all the gases is 10. If the partial pressure of A and B are 3.0 and 1.0 atm respectively and if C has mol. wt. of 2.0, what is the weight of C in g present in the mixture ?$ (1) $6$ (2) $8$ (3) $12$ (4) $3$ 145. $A container having volume V contains an ideal gas at 1 atm pressure. It is connected to another evaculated container having volume 0.5 d m^{3} through a tube having negligible volume. After some time the first container is found to have pressure 570 mm of Hg. If temperature is constant, V is :$ (1) $1.0 d m^{3}$ (2) $1.5 d m^{3}$ (3) $2.0 d m^{3}$ (4) $2.5 d m^{3}$ 146. $An open vessel at 27°C is heated until two fifth of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant, the temperature at which the vessel has been heated is:$ (1) $750 K$ (2) $750°C$ (3) $500 ºC$ (4) $500 K$ 147. $A sealed flask with a capacity of 2 d m^{3} contains 11 g of propane gas. The flask is so weak that it will burst if the pressure becomes 2 MPa. The minimum temperature at which the flask will burst is _______°C. [Nearest integer](Given: R = 8.3 J K^{- 1} m o l^{- 1} . Atomic masses of C and H are 12u and lu respectively.) (Assume that propane behaves as an ideal gas.)$ 148. $The pressure of a moist gas at 27°C is 4 atm. The volume of the container is doubled at the same temperature. The new pressure of the moist gas is .... x 1 0^{- 1} atm. (Nearest integer)(Given : The vapour pressure of water at 27°C is 0.4 atm)$ 149. $The number of statement's, which are correct with respect to the compression of carbon dioxide from point (a) in the Andrews isotherm from the following is_________. A. Carbon dioxide remains as a gas upto point (b) B. Liquid carbon dioxide appears at point (c) C Liquid and gaseous carbon dioxide coexist between points (b) and (c) D. As the volume decreases from (b) to (c), the amount of liquid decreases$ 150. $Two flasks I and II shown below are connected by a valve of negligible volume. When the valve is opened, the final pressure of the system in bar is x \times 1 0^{- 2} . The value of is ____. (Integer answer) [Assume-Ideal gas; 1 bar = 1 0^{5} Pa; Molar mass o f N_{2} = 28.0 g m o l^{- 1};R = 8.31 J m o l^{- 1} K^{- 1}]$