States of Matter PYQs Set 5 (PDF)

Set 5 of 7 · Questions 121-150 of 196

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Mere Teacher · Previous Year Questions NEET Chemistry · States of Matter · Set 5 (Q121-150)
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121. $Which one of the following statements is not true about the effect of an increase in temperature on the distribution of molecular speeds in a gas ?$ (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) $The most probable speed increases$ 122. $At what temperature root mean square speed of N_{2} gas is equal to that of propane gas at S.T.P. conditions.$ (1) $173.7°C$ (2) $173.7 K$ (3) $S.T.P.$ (4) $- 40°C$ 123. $For one mole of a van der Waals gas when b = 0 and T = 300 K, the PV vs.1/V plot is shown below. The value of the vanderWaals constant a (atm. l i t e r^{2} m o l^{-2}) :$ (1) $1.0$ (2) $4.5$ (3) $1.5$ (4) $3.0$ 124. $For 1 mol of gas, the plot of pV vs p is shown below, p is the pressure and V is the volume of the gas. What is the value of compressibility factor at point A?$ (1) $1 - \frac{a}{R T V}$ (2) $1 + \frac{b}{V}$ (3) $1 - \frac{b}{V}$ (4) $1 + \frac{a}{R T V}$ 125. $A quantity of gas is collected in a graduated tube over the mercury. The volume of gas at 18 ºC is 50 ml and the level of mercury in the tube is 100 mm above the outside mercury level. The barometer reads 750 torr. Hence, volume at S.T.P. is approximately :$ (1) $22 ml$ (2) $40 ml$ (3) $20 ml$ (4) $44 ml$ 126. $The combination of plots which does not represent isothermal expansion of an ideal gas :$ (1) $(B) and (D)$ (2) $(A) and (C)$ (3) $(B) and (C)$ (4) $(A) and (D)$ 127. $A gaseous mixture of three gases A, B and C has a pressure of 10 atm. The total number of moles of all the gases is 10. If the partial pressure of A and B are 3.0 and 1.0 atm respectively and if C has mol. wt. of 2.0, what is the weight of C in g present in the mixture ?$ (1) $6$ (2) $8$ (3) $12$ (4) $3$ 128. $A container having volume V contains an ideal gas at 1 atm pressure. It is connected to another evaculated container having volume 0.5 d m^{3} through a tube having negligible volume. After some time the first container is found to have pressure 570 mm of Hg. If temperature is constant, V is :$ (1) $1.0 d m^{3}$ (2) $1.5 d m^{3}$ (3) $2.0 d m^{3}$ (4) $2.5 d m^{3}$ 129. $An open vessel at 27°C is heated until two fifth of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant, the temperature at which the vessel has been heated is:$ (1) $750 K$ (2) $750°C$ (3) $500 ºC$ (4) $500 K$ 130. $1 mol of a gaseous aliphahatic compound C_{n} H_{3 n} O_{m} is completely burnt in an excess of oxygen. The contraction in volume is (assume water get condensed out)$ (1) $(1 + \frac{1}{2} n - \frac{3}{4} m)$ (2) $(1 + \frac{3}{4} n - \frac{1}{4} m)$ (3) $(1 - \frac{1}{2} n - \frac{3}{4} m)$ (4) $(1 + \frac{3}{4} n - \frac{1}{2} m)$ 131. $The variation of compressibility factor (Z) with pressure (p in bar) for some gases are shown in the figure below. Identify the gases (A), (B) and (C) respectively$ (1) $real gas, N_{2}, CO_{2}$ (2) $ideal gas, H_{2}, CO_{2}$ (3) $ideal gas, CO_{2}, H_{2}$ (4) $real gas, H_{2}, CO_{2}$ 132. $If the partition is removed the average molar mass of the sample will be (Assume ideal behaviour).$ (1) $\frac{5}{3} g/mol$ (2) $\frac{10}{3} g/mol$ (3) $\frac{3}{2} g/mol$ (4) $3 g/mol$ 133. $Which one of the following graphs is not correct for ideal gas? d Density, P Pressure, T Temperature$ (1) $II$ (2) $III$ (3) $I$ (4) $IV$ 134. $From the following plots, find the correct option$ (1) $T_{1} > T_{2} : P_{1} > P_{2}$ (2) $T_{1} > T_{2} : P_{2} > P_{1}$ (3) $T_{2} > T_{1} : P_{2} > P_{1}$ (4) $T_{2} > T_{1} : P_{1} > P_{2}$ 135. $In a 1 L vessel, 10 moles of methane and 50 moles of O_{2} are present. The number of moles of O_{2}, water and CO_{2} present in the vessel are respectively after the vessel was heated to burn methane completely.$ (1) $30, 20, 20$ (2) $30, 20, 10$ (3) $20, 30, 10$ (4) $20, 10, 30$ 136. $A plot of volume of the gas versus T (K) is shown below. Which of the options is correct for the plot?$ (1) $p_{1} < p_{2} < p_{3}$ (2) $p_{3} < p_{2} < p_{1}$ (3) $p_{1} = p_{2} \neq = p_{3}$ (4) $p_{1} = p_{2} = p_{3} = 0 at 273 K$ 137. $10 ml of gaseous hydrcarbon is exploded with 100 ml O_{2} . The residual gas on cooling is found to measure 95 ml of which 20 ml is abosrbed by KOH and the reminder by alkaline pyrogallol. The formula of the hydrocarbon is :$ (1) $C H_{4}$ (2) $C_{2} H_{6}$ (3) $C_{2} H_{4}$ (4) $C_{2} H_{2}$ 138. $An evacuated glass vessel weighs 40.0 g when empty, 135.0 g when filled with a liquid of density 0.95 g m L^{- 1} and 40.5 g when filled with an ideal gas at 0.82 atm at 250 K. The molar mass of the gas in g m o l^{- 1} is : (Given : R = 0.082 L atm K^{- 1} m o l^{- 1})$ (1) $35$ (2) $50$ (3) $75$ (4) $125$ 139. $Points I, II and III in the following plot respectively correspond to (V_{mp} : most probable velocity).$ (1) $VmpofN2 (300 K); Vmp of O_{2} (400 K); Vmp of H_{2} (300 K)$ (2) $VmpofO2 (400 K); Vmp of N_{2} (300 K); Vmp of H_{2} (300 K)$ (3) $VmpofN2 (300 K); Vmp of H_{2} (300 K); Vmp of O_{2} (400 K)$ (4) $VmpofH2 (300 K); Vmp of N_{2} (300 K); Vmp of O_{2} (400 K)$ 140. $Out of the two compounds below the vapour pressure of (B) at a particular temperature is$ (1) $higher than that of (A)$ (2) $lower than that of (A)$ (3) $higher or lower than (A), depending on the size of the vessel$ (4) $same as that of (A)$ 141. $The given figure shows the Maxwell distribution of molecular speeds of a gas at three different temperatures T_{1}, T_{2} and T_{3} . The correct order of temperature is$ (1) $T_{1} > T_{2} > T_{3}$ (2) $T_{1} > T_{3} > T_{2}$ (3) $T_{3} > T_{2} > T_{1}$ (4) $T_{2} > T_{3} > T_{1}$ 142. $The compressibility factor for a real gas at high pressure is :$ (1) $1 + RT/pb$ (2) $1$ (3) $1 + pb /RT$ (4) $1 -pb/RT$ 143. $Initially, the root mean square (rms) velocity of N2 molecules at certain temperature is u. If this temperature is doubled and all the nitrogen molecules dissociate into nitrogen atoms, then the new rms velocity will be :$ (1) $2 u$ (2) $14 u$ (3) $u / 2$ (4) $4 u$ 144. $What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?$ (1) $89.6 L$ (2) $67.2 L$ (3) $44.8 L$ (4) $22.4 L$ 145. $Plot of Maxwell's distribution of velocities is given : Which of the following is correct about this plot?$ (1) $f_{1} > f_{2}$ (2) $T_{1} < T_{2}$ (3) $V_{1} < V_{2}$ (4) $T_{1} > T_{2}$ 146. $Match the following. List-I: (A) Viscosity (B) Ideal gas behaviour (C) Liquefaction of gases (D) Charles law. List-II: P. Critical temperature Q. Isobar R. Compressibility factor S. kg s^{- 2} T. kg m^{- 1} s^{- 1} . The correct answer is (A, B, C, D)$ (1) $S R P Q$ (2) $T R P Q$ (3) $T R Q P$ (4) $S R Q P$ 147. $An ideal gas expands by performing 200 J of work, during this internal energy increases by 432 J . What is enthalpy change?$ (1) $200 J$ (2) $232 J$ (3) $432 J$ (4) $632 J$ 148. $An open vessel at 27° C is heated until two-fifth of the air in it has been expelled. Assuming that the volume of the vessel remains constant, find the temperature to which the vessel has been heated?$ (1) $500° C$ (2) $500 K$ (3) $750° C$ (4) $750 K$ 149. $At the sea level, the dry air mass percentage composition is given as nitrogen gas: 70.0, oxygen gas: 27.0 and argon gas: 3.0. If total pressure is 1.15 atm, then calculate the ratio of following respectively: (i) partial pressure of nitrogen gas to partial pressure of oxygen gas (ii) partial pressure of oxygen gas to partial pressure of argon gas (Given: Molar mass of N, O and Ar are 14, 16 and 40 g mol^{- 1} respectively.)$ (1) $5.46, 17.8$ (2) $2.96, 11.2$ (3) $4.26, 19.3$ (4) $2.59, 11.85$ 150. $The statement that is not correct is$ (1) $compressibility factor measures the deviation of real gas from ideal behaviour$ (2) $van der Waals constant ' a' measures extent of intermolecular attractive forces for real gases$ (3) $critical temperature is the lowest temperature at which liquefaction of a gas first occurs$ (4) $Boyle point depends on the nature of real gas.$