Question

Please show all work

A.)Place the following in order of decreasing standard molar entropy.

NaCl(s) Na₃PO₄(aq) NaCl(aq)

	a.NaCl(aq) > Na3PO4(aq) > NaCl(s)
b.	NaCl(aq) > NaCl(s) > Na3PO4(aq)
c.	Na3PO4(aq) > NaCl(aq) > NaCl(s)
d.	NaCl(s) > NaCl(aq) > Na3PO4(aq)
e.	NaCl(s) > Na3PO4(aq) > NaCl(aq)

B.)Calculate the ΔG°_rxn using the following information.

	2 H2S(g)	+	3 O2(g)	→	2 SO2(g)	+	2 H2O(g)
ΔH°f(kJ/mol)	-20.6				296.8		-241.8
S°(J/mol∙K)	205.8		205.		248.2		188.8

ΔG°_rxn = ?

a.	+108.2 kJ
b.	+196.8 kJ
c.	-147.1 kJ
d.	+676.2 kJ
e.	-466.1 kJ

C.)Calculate the ΔG∘rxn for the reaction using the following information.

4HNO3(g)+5N2H4(l)→7N2(g)+12H2O(l)

ΔG∘f(HNO3(g)) = -73.5 kJ/mol;
ΔG∘f(N2H4(l)) = 149.3 kJ/mol;
ΔG∘f(N2(g)) = 0 kJ/mol;
ΔG∘f(H2O(l)) = -273.1 kJ/mol.

	a.+110.7 kJ
b.	-3.298 x 103 kJ
c.	-954.7 kJ
d.	+2.845 x 103 kJ
e.	-312.9 kJ

Answer 1

A.)Place the following in order of decreasing standard molar entropy.

Entropy is a mesure of order/chaos

the more complex a molecule is, the higher entropy- The phase is also taken into consideration

From the list:

NaCl(s) --> Solids have ordered lattices and crystal formation, low entropy

Na3PO4(aq) --> aqueous solution are chaotic, expect 3 ions of Na+ and 1 ion of PO4-3 in solution

NaCl(aq) --> similar, but less chaos since there are only 2 ions

From the list

The most chaotic -->

Na3PO4(aq) > NaCl(aq) > NaCl(s)

B.)Calculate the ΔG°_rxn using the following information.

dG = dH - T*dS

dG = (Hproducts - Hreactants) - T*(dSprducts - Sreactants )

dG =(2*296.8-241.8*2 - 2*(-20.6) -3*0) - 298*(188.8*2 + 2*248.2 - 2*205.8 - 3*205)/1000

dG = 196.6748 kJ/mol

C.)Calculate the ΔG∘rxn for the reaction using the following information.

4HNO3(g)+5N2H4(l)→7N2(g)+12H2O(l)

dG = Gproducts - Greactants

dG = 7N2(g)+12H2O(l) - (4HNO3(g)+5N2H4(l))

dG = (7*0 + 12*(-273.1) - ((4*-73.5) + (5*149.3))

dG = -3729.7 kJ/mol

b.	-3.298 x 103 kJ