Title DPP-10 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 10 1 (c) (vav)1 (v(av) )2 = T1 T2 Given, T1 = 150 + 273 = 423 K T2 = 50 + 273 = 323 K ∴ (vav)1 (vav)2 = T1 T2 = 423 323 = 1.14 1 2 (c) P′ = mole fraction × PM The gas having higher mole fraction has high partial pressure. 3 (c) There are 6 A atoms on the face centres removing face centred atoms along one of the axes means removal of 2 A atoms Now, number of A atoms per unit cell = 8 × 1 8 + 4 × 1 2 = 3 (corners) (face- centred) Number of B-atoms per unit cell = 12 × 1 4 + 1 = 4 (edge centred) (body Centred) Hence, the resultant stoichiometry is A3B4 4 (c) CH3OCH3 lacks H-bonding hence, it is most volatile, so it has maximum vapour pressure 5 (c) Molecular mass of N2 = 28, CO = 28 Number of molecules of N2 Topic :- STATES OF MATTER Solutions
(V = 0.5 L, T = 27°C, p = 700 mm) = n Number of molecules of N2 (V = 1 L, T = 27°C, p = 700 mm) = 2n 7 (b) uav = 8RT πM So, uav(O2) = 8RT π × 16 urms = 3RT M so urms(N2) = 3RT 14 uav(O2) urms(N2) = 8 × 14 π × 16 × 3 = ( 7 3π) 1/2 8 (a) r1 r2 = [ M2 M1 ] 9 (c) van der Waals’ equation for one mole of a gas is [p + a V 2] [V ― b] = RT Where, b is volume correction. It arises due to effective size of molecules. 10 (b) P and T both are doubled; Use V = nRT P 11 (d) R is universal constant and has different values in different units. 12 (a) Radius of Na(if bcc lattice) = 3a 4 = 3 × 4.29 4 Å 13 (c) pV = nRTor pV = w M RT or M = w V RT p or M = d RT p d = 1.964 g/dm3 = 1.964 × 10―3 g/cc p = 76 cm Hg = 1 atm R = 0.0812 L atm K ―1 mol―1 = 82.1 cc atm K ―1 mol―1
T = 273 K M = 1.964 × 10―3 × 82.1 × 273 1 = 44 The molecular weight of CO2 is 44. So, the gas is CO2. 15 (a) uav ∝ T ∴ u1 u2 = 1 2 ∴ u2 = 2 u1 = 1.4 u1 16 (d) Mass of the gas is not known. 17 (c) Crystalline solids such as NaCl, BaCl2 etc, will show anisotropy 18 (c) The radius ratio for coordination number 4, 6 and 8 lies in between the ranges 0.225 ― 0.414, 0.414 ― 0.732 and 0.732–1.000 respectively 19 (c) Mole ratio = Molecule ratio = w/32 w/28 = 7 :8