Question

13 7. If a reaction has AS-100 J/K and is spontaneous, what must be true of the surroundings? A) ASurnroundings 100 J/k D) ASguroundings <-100 J/k C) &Surroundings 100 J/k B) ASurroundings> -100 J/K E) ASurroundings< 100 J/k 8. Use the following table of S values to calculate the value of AS for each of the following reactions. Nz0601 A. 2NO(g) + H2(g)--+ N20(g) + H2O (g) ΔΗ"(rind) 346 B. 2N20s(g) → 4NO2(g) + O2 (g) C. HI(g) from its elements S ecies K.(J/moll Species ΔΗ"(chem 346 mol) 0 218.0 0 249.2 H2le 130.6 114.6 205 O8161 O(g) N2(8) 191.5 0 153.2 210.7 472.7 90.25 NO(B) merg)一一一1188.7 HO()69 NO(g) 1219.7 |-241.8 285.8 82.05 ー NO (8) 240.0 33.2 N20(g)304.2 9.2 116.14 O 260.58 62.4 Hle) 206.3 25.9 9. Calculate AS sys AS surr, and AS unlverse for the reactions in the previous problem at 25°C: 10. Which of the following reactions in problem 9 are spontaneous? Explain.

Please answer 7-10 if possible, thank you!

Answer 1

Q7)If the reaction is spontaneous DS total > 0 , that is positive value.

Given fora spontaneous reaction, DS system is negative , DS = -100J/K

then DS surroundings must be greater than +100 J/K so that DS total = DS system + DS surr >0

Thus option A is correct.

Q8)

DS rxn = S of products - S of reactants

A) The reaction is

2NO + H2 --------> N2O + H2O

DSrxn = (219.7+69.61) -(2x210.7+130.6)

= -262.39J

B) 2N2O5 ----------> 4NO2 + O2

Ds rxn = (4x240 +205) -2x11

=+1143 J

C) H2 + I2 -----> 2HI

DS rxn = 2x206.3 -(130.6+260.58)

= +21.42 J