Tiêu đề DPP-2 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 2 1 (c) Volume of balloon = 4 3 πr 3 = 4 3 × 22 7 × ( 21 2 ) 3 = 4851 mL Volume of the cylinder containing gas =2.82 L = 2820 mL Volume at STP = V1 = 2820 × 273 300 × 20 = 51324 mL Volume of the gas that will remain in the cylinder after filling balloons is equal to the volume of cylinder, ie, 2820 mL Available hydrogen for filling = 51324 ― 2820 = 48504 mL Number of balloons = 48504 4851 ≈ 10 2 (a) Pdry gas = Pwet gas ― PH2O 3 (b) It is a characteristic of liquid crystal 4 (a) T2 = T1 + 1; P2 = P1 + 0.4 P1 100 Now use, P1V1 T1 = P2V2 T2 assuming V1 = V2 5 (d) In a unit cell, W atoms at the corner = 1 8 × 8 = 1 O-atoms at the centre of edges = 1 4 × 12 = 3 Na-atoms at the centre of the cube =1 W : O : Na =1 : 3 : 1 Hence, formula = NaWO3 6 (a) Topic :- STATES OF MATTER Solutions
pV = nRT V = same R = constant T = same p ∝ n or p ∝ w M but w is same. So, p ∝ 1 M pCH4 pO2 = MO2 MCH4 = 32 16 = 2 1 7 (d) u1/u2 = [ T1 T2 ] 8 (c) P′H2O = PM × 1 100 = 760 × 1 100 = 7.6 mm of Hg 9 (b) Rate of diffusion ∝ 1 molecular mass ∴ Order of diffusion :H2 > CH4 > SO2 and amount left is in the order SO2 > CH4 > H2 Hence, order of partial pressure is pSO2 > pCH4 > pH2 10 (a) w = 22 g; V = 1 litre, T = 298 K using PV = w m RT (for CO2) P × 1 = 22 44 × 0.0821 × 298 ∴ PCO2 = 12.23 atm ∴ Pin bottle = PCO2 + atm. pressure = 12.23 + 1 = 13.23 atm 11 (d)
A fact for deviations from ideal gas behaviour. 12 (c) Closest approach in bcc lattice = 1 2 of body diagonal = 1 2 × 3a = 3 2 × 4.3 = 3.72 Å 13 (c) VA tA × tB VB = MB MA 10 20 = MB 49 MB = 49 4 = 12.254 14 (d) This is one of the limitation of van der Waals’ equation. 15 (c) Frenkel defect is observed in the crystals in which the radius ratio is low 16 (b) Graham’s law of diffusion of gases r1 r2 = M2 M1 = d2 d1 17 (a) d p = M R Let density of gas B = d So, density of gas A = 2d And molecular weight of A = M So molecular weight of B = 3M pA = MA dA and pB = MB dB pA pB = MA dA × dB MB = M 2d × d 3M = 1 6 18 (c) Real gases do not follow gas laws at all temperature and pressure conditions due to two wrong assumptions in kinetic molecular theory of gases : (i) The volume occupied by gas molecules is negligible. It is not true because gas
molecules do occupy small volume. (ii) The forces of attraction between gas molecules are zero. It is not true because attractive forces are present between molecules of real gases. 19 (d) Boyle’s law, Charles’ law and Avogadro’s law can be proved on the basis of kinetic theory of gases.