(show all your works for parts a and part d and please don\'t skip any questions

Question

(show all your works for parts a and part d and please don't skip any questions. Thanks you)

a. without using data, arrange each group in the order of increasing standard molar entropy, S0, and explain your order:

(i) fructose C6H12O6, ribose C5H10O5, lactose C12H22O11

(ii) [Mg(s)+S(s)+2O2(g)], [MgO(s)+SO3(g)], MgSO4(s)

(iii) As(s), Bi(s), Sb(s)

(iv) dihydrogen phosphate ion, hydrogen phosphate ion, phosphate ion

combustion of methanol, CH3OH(l)

formation of formaldehyde. CH2O(g) from its elements

d. define the thermodynamic state function "free energy, G"

Explanation / Answer

a) Molecules having more entropy will have entropy compared to molecules having less number of atoms. So the order of increased entropy is C5H10O5< C6H12O6< C12H22O11.

b) Entropy is degree of disorder. Entrpoy for soilids is less than liquids and the entropy of liquids in turn is less than gases.

MgSO4< MgO+SO3(g)( Only one molecule of SO3) < Mg+S+2O2(g)

c) Atoms having higer atomic number will have less entropy than atoms having lower atomic number. Atomic numbers are shown in brackets for the respective elements.

Arsenic (33), Bismuth (83), Antimony (53).

Hence   entropy sequence is Bismuth < Antimony<Arsenic

d) The balanced reaction is 3NO2 (g) + H2O(l)----------->2HNO3(aq)+ NO(g)

entropy change= sum of entropy of products- sum of entropy of reactants

= 2*146.44+1*211 - (3*240 +70)= -286 J/K

e) The combustion of ethanol liquid can be represented as

C2H5OH + 3O2-------> 2CO2(g) + 3H2O(g)

So entropy change = 2*entropy of CO2 + 3* entropy of H2O- ( entropy of C2H5OH+ 3* entropy of O2)

=2*214+3*189- (161+3*205)= 219 J/K

Formaldehyde formed from its elements can be represented as

C(s)+H2(g)+1/2O2(g)--------> CH2O(g)

entropy change = entropy of CH2O- ( entroy of C + Entroiy of H2(g) +0.5* entropy of O2)

=219- ( 6 +130+ 0.5*205.2)=-19,6 J/K

e) Delta S0 = entropy of products - entroy of reactants

So entropy of products increases with temperature and entropy of reactants also increases and the net results is no change in entropy with increased temperature

f) state function is a function which is independent of path. It is denoted by deltaG

deltaG= H- TS

=

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