Question

13. The standard molarentropy of lead(II) bromide (PbBr₂) is 161 J/mol � K.What is the entropy of 2.45 g of PbBr₂?

a.	+1.07 J/K	d.	�161 J/K
b.	�1.07 J/K	e.	0 J/K
c.	+161 J/K

14. CalculateDS⁰ for theformation of 1 mol of HI(g) from its elements given thefollowing information:

S⁰[H₂(g)] = 131J/mol?K

S⁰[I₂(s)] = 116J/mol?K

S⁰[HI(g)] = 206 J/mol?K.

A) 82 J/K B) 165 J/K C)247 J/K D) 329 J/K

15. For which reactionis DS_sys >0?

A)CH₄(g) + 2 O₂(g) ?CO₂(g) + 2 H₂O(l)

B)NH₃(g) + HCl(g) ?NH₄Cl(s)

C) 2NH₄NO₃(s) ? 2 N₂(g) + O₂(g) + 4H₂O(g)

D) HCl(aq) + NaOH(aq)? NaCl(aq) +H₂O(l)

16. In a biochemicalreaction, A + B C with ?G= 30 kJ/mol. Which of the followingreactions might be effectively coupled to this reaction so that itbecomes more spontaneous?

I.	C + D are the reactants,and B + E are the products	?G= -40kJ/mol
II.	C + D are the reactants,and B + E are the products	?G= +40kJ/mol

a.	I only
b.	II only
c.	I or II
d.	Neither I nor II canincrease spontaneity.
e.	No coupling is required asthe reaction is already spontaneous.