SO3(g) + H2O(l) ? H2SO4(ia) SO3(g) + H2O(l) ? H2SO4(l) a) compare between H2SO4(

ID: 1074078 • Letter: S

Question

SO3(g) + H2O(l) ? H2SO4(ia) SO3(g) + H2O(l) ? H2SO4(l)
a) compare between H2SO4(ia) and H2SO4(l), what are the differeances between them. b) explain which of the two choices would represent the actual process and why? a) compare between H2SO4(ia) and H2SO4(l), what are the differeances between them. b) explain which of the two choices would represent the actual process and why? SO,(g) H2O() H2SO4 (ia) Temp TAS 300 -228.36 308.51 -135.80 4.44E+23 -9.26E+01 333E-03 54.45 244.39 357.87 -119.14 605E-17 1.25E+02 2.86E-03 40.94 400 -262.12 -405.18 -100.05 1.17E+13 -1.62E+02 2.50E-03 30.09 281.58 -450.96 500 302.82 495.68 -54.97 5.54E+05 2.48E+02 2.00E-03 113.22 550 325.98 539.81 -29.08 5.29E+02 -2.97E+02 1.82E-03 6.36 600 351.43 -584.06 -0.99 1.22E+00 3.50E+02 1.67E-03 0.20 -5.433 650 379.18 -628.47 29.33 4.40E-03 -4.09E +02 1.54E-03 700 -408.48 -671.88 61.84 2.43E-05 -4.70E+02 1.43 -03 -10.63 750 4139.33 -714 44 96.50 190E-07 5.36E 02 1.33E-03 115 48 800 -471.72 -756.24 133.27 1.98E-09 -6.05E+ 02 1.25E-03 -20.04 850 505.65 -797136 117211 2.64E-11 E6.228E+02 118E-03 .24.36 837.89 950 578.08 -877.87 255.89 8.49E-15 -8.34E+02 1.05E-03 -32.40 1000 -616.58 -91736 300.228 1494E-16 -9.17E+02 1.00E-03 -36183 Temp. TAS 132.38 -169.74 -81.46 1.53E+14 -5.09E+01 3.33E-03 32.66 130.72 -164.98 -64.72 2.83E+08 -6.60E+01 2.50E-03 19.46 450 129.80 162.83 -56.534 365E+06 7.33E+01 2.22E-03 15.11 550 128.46 160.09 -40.41 6.88E +03 -8.81E+01 1.82E-03 8.84 600 -128.59 160.31 -32.40 6.63 E 02 -9.62E+01 1.67E-03 6.50 650 -1 -161.66 -24.35 9.06E +01 -1.05E+02 1.54E-03 4.51 129.43 130.27 162.90 -16.24 1.63E +01 14E +02 1.43E-03 131.09 9.76E-01 32E 02 1.25E-03 850 132.73 -166.09 8.44 EE.03E-01 -1 41E+02 1.18E-03 -1.20 133.56 167.03 16.77 1.06E-01 -1.50E 02 1.11E-03 -2.24 950 134.39 -167.93 25.15 4.14E-02 -1.60E+02 1.05E-03 -3.18

Explanation / Answer

From the calculation of the thermodynamic parameters for these reactions:

SO3(g) + H2O(l) H2SO4(ia)

SO3(g) + H2O(l) H2SO4(l)

a) Compare between H2SO4(ia) and H2SO4(l)

H2SO4(ia)

H2SO4(l)

More exothermic

Less exothermic

1Hf is more negative

1Hf is less negative

S0 is more negative

S0 is less negative

G0 is more negative

G0 is less negative

The value for K is large, products dominate the mixture.

The value for K is smaller than (ia), products is less dominate the mixture.

TS is more

TS is less

In this caseH0 and S0 for both reactions is negative, so reaction proceeds at low temperature.

b) Reaction (ia) represent the actual process

ENTHALPY OF REACTION-

[1Hf(H2SO4 (aq))] - [1Hf(SO3 (g)) + 1Hf(H2O (l))]

[1(-909.27)] - [1(-395.72) + 1(-285.83)] = -227.72 kJ

-227.72 kJ (exothermic)

ENTROPY CHANGE-

[1Sf(H2SO4 (aq))] - [1Sf(SO3 (g)) + 1Sf(H2O (l))]

[1(20.08)] - [1(256.65) + 1(69.91)] = -306.48 J/K

-306.48 J/K (decrease in entropy)

FREE ENERGY OF REACTION (AT 300 K)

From Gf° values:

[1Gf(H2SO4 (aq))] - [1Gf(SO3 (g)) + 1Gf(H2O (l))]

[1(-744.63)] - [1(-371.08) + 1(-237.18)] = -136.37 kJ

-136.37 kJ (spontaneous)

From G = H - TS:

-136.34 kJ (spontaneous)

EQUILIBRIUM CONSTANT, K (AT300 K)

7.8E+23

This process is favorable at 300K