Question

Equilibrium constants can be measured for the dissociation of Lewis acid-base complexes such as the dimethyl ether complex of BF3, (CH3)20+BF3. The value of K (here Kp) for the reaction is 0.17 at 125 °C. (CH3)20+BF3(g) =BF3(g) + (CH3)20(g) Is BF3 a Lewis acid or a Lewis base? Lewis acid Lewis base Correct A Lewis acid is an electron pair acceptor. B has an incomplete octet in BF3 and, as an electron deficient species, is an electron pair acceptor in the reverse reaction, so BF3 is a Lewis acid. b Is (CH3)20 a Lewis acid or a Lewis base? Lewis acid Lewis base Correct A Lewis base is an electron pair donor. The O atom in (CH3)2O has two lone pairs and is an electron pair donor in the reverse reaction, so (CH3)20 is a Previous Next >

Answer 1

Yes, BF3 is a lewis acid. B has incomplete octet, it can accept electron pair so. Bf3 is a lewis acid (CH3)20 is a lewis base. Oxygen has lone pair of electrons, which it can donate, so (CH3)20 is a lewis base. (CH3)20 → BEJ 40) 3 Bfalg) + (CH3)2014) Given initially complex of lg is kept a FO.Sml flock. in Molarity of compler = mass Molecular mass of complea Volanell ت عماMo ها: 0 - 0:012 M. 11491 mo _ | 70.5x10-32 BF319) + (CH3)2 0 (CH3),0 >> Bf31g) t:0 0:012 tzteg (0.012-x) [pixosUsing ideal gas eq.2. So, pressure = MRT PV=nRT . RICH3/20 BF3 = 10:012-2) RY PBF3 - X RT PICH3/20 = XRT

Given_Kp 2012._ Kp = (PBF3) (Picha), o) _P(CH2) 20 -> BF3_ = 0.17 = = (ART) (art) 10.012-2) BI x² RT (0.012-7) =) 0.17 = ?10.0821) (398) - 100012-22) 0.00204 - 001722 = 3206822 3268x2 +0.172 -0.00204 20 = = By solving i weget_ this equation 22 -0.0109 or 220.0057 acceptable because So, x a= 0.0057 is only can't be negative. Is P(CH2)20 → BF3 = 10.012 -0.0057) RT = 0o21 atm. PBF3 = (0.0057) RT 0.19 atm = PICH3)20 = 10.0057) RT o.19 atm P Total = 0. 21 +0.19 +0.19 0.59 atm.

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