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ermo (g) + 1302 (g) 8CO2 (g) + 10 HO (9) a) Estimate the H\'nn at 25°C using bon

ID: 699195 • Letter: E

Question

ermo (g) + 1302 (g) 8CO2 (g) + 10 HO (9) a) Estimate the H'nn at 25°C using bond dissociation energies energies per mole of bonds are given: C-H 413 kJOC = 463 kJ. The following average bond = 346 kl. C-o-799 kJ: O-o 498 kt Estimate the S.rxn at 25.c s"(c.H10 (g)) = 3 10 3 JK s. (O2 (g))-205 0 JK, s.(CO2 (g)) = 21 3 6 J/K: S' (H O (g))- 188.7 J/K b) Is this reaction spontaneous under standard conditions? If not when is this reaction said to be spontaneous. c) 3. The titration of 50.0mL of O.100M acetic acid (Ka-1.8 x 10) with 0.100M NaOH is carried out in a chemistry laboratory. Calculate the pOH of the solution when 50.0 mL of NaOH is added.

Explanation / Answer

2C4H10(g) + 13O2(g) ---> 8CO2(g) + 10H2O(g)

DH0rxn = (20*DHdis,C-H)+(6*DH0dis,C-C)+(13*DH0dis,O=O)+(16*DH0f,C=O)+(20*DH0f,O-H)

       = (20*413+6*346+13*498)+(16*-799+20*-463)

       = -5234 Kj

DS0rxn = (8*s0,CO2+10*S0,H2O)-(2*S0,C4H10+13*S0,O2)

       = (8*213.6+10*188.7)-(2*310.3+13*205)

       = 310.2 J/K

DG0 = DH0-TDS0

    = (-5234)-(298*310.2*10^-3)

= -5326.44 kj

as DG = -ve, the process is spontaneous.