Question

Need help with the following THREE questions (19,20, and 21)

19. Use the standard reaction enthalpies given below to determine A rxn for the following reaction: 2 S(s) + 302(g) - 2 503() AH rxn = ? Given: 06-298) SO2(e) - S(s) + O2(8) AHørxn = +296.8 kJ -1978 2 SO2(8) + 02() + 2 503(E) AHørxn = -197.8 kl - 791.4 A. -494.6 kJ B. -692.4 kJ C.-791.4 kJ D. +1583 kl E. -293.0 kJ 20. Use the information provided to determine AHrs for the following reaction: CH.() + 4Cl2 → CCI.) + 4 HCC) AH rx = ? + Substance AH (kJ) 46-92) mol -75 CH4 (8) CCI.(g) - 389kj. -96 46-92) + (-76) + 75 -388 -464+25 HCI() -92 A. -263 k) B -113 kJ C. +113 kJ D. -389 kJ E +389 kJ 21. Calculate the De Broglie wavelength of a bucky-ball, a spherical molecule with molecular formula of Co, traveling at a velocity of 25.0 m/s. The molar mass of Co is 720.66 /mol. A. 2.2 x 10-11 m B. 3.7 x 10-38 m C. 3.7 x 10-19 m D. 2.7 x 10-35 m E. 3.1 x 10-4 m 2006.com trans aad - - 1.2x10-24 n = 6.606x10-34 my 1.28 10-2* (25h/ -10 22x10-10 -2.2 roll

Answer 1

The complete step wise calculation in detail is given as below:-

① Reactions are given by:- 9S(s) + 3O2 (9) > 2SO3 (9) AH,ụn =3 - 0 S029) -→ 5(S) + O2(3) OHöxn = +29 6.8KJ - © 2502(9) +02(8) ► 2503 (9), Ahixn = -197.8% J From the above equations, we have 3 - ©x2 + 2 SÓ 2 (9) + O2(3) – 2 8069) > 2503 (9) — 250) – 20269)

on 2565) + 302 (8) - > 2803 9) - 0 DM xxn = -197.8kJ - 2 x 296-8kJ since, ① = ② – 2x②) or shoxen - -(197.8 - 593.6)kJ = -791.4 kJ So, oHºrxn = -791.4 kJ Then the correct option will be ③ -791.4KJ.

(0 reaction is given by:- chuca) +u Cle (g) → ccly (2) + unce ) Ahsxn = (al product) - (Ah reactant) ={E96 +486-92)] = [(-75) -o]} kolmel. =(-464 +75) kJ1 mol = -389 kJ or Ahorxh = -389 kJ So, the correct option will be 0 -389 kJ

@ It is given that, velocity () = 25.0 m/s Planck's constant (h) = 6.626 X10 34 Jig molar mass of C60 = 720.66 g/mol = 0.72066 kg/mol since 1kg=1000g Imole = 6.023 X 1023 atoms or molecules Then mass (mi= 0.72066 kg = 112 x10-24 kg ta 6.023x1033 So, the De Broglie wave length (1) is givenby

x= h - (Where d = De Broglie wavelength) , putting all the values in the above equation = (6.626 X1034 J.8) (1•2 x1024 kg)x(25,0718) Ixlo on on 11 - 6626 30 om = 2.20 X1olm / or d = 2.20 xlolm So, the correct option will be 2.2 xlo-11 m.