Predict the sign of S°, if possible, for each of the following reactions. If you cannot predict the sign for?

Question

any reaction, state why.

(a) 2 SO3(g) 2 SO2(g) + O2(g)

positive
negative
not predictable

(b) C2H5OH(l) + 3 O2(g) 2 CO2(g) + 3 H2O(l)

positive
negative
not predictable


(c) P4(g) P4(s)
positive
negative
not predictable


(d) 2 NaHCO3(s) Na2CO3(s) + H2O(g) + CO2(g)
positive
negative
not predictable

Answer 1

Lancenigo di Villorba (TV), Italy

Your question interests STANDARD ENTROPY's CHANGEs.

REACTION a)
2 SO3(g) ---> 2 SO2(g) + O2(g)
POSITIVE.
The Chemical Products contain a GAS-MOLE's NUMBER GREATER THAN Reactant's One : the System-Disorder's Degrees rises.

REACTION b)
C2H5OH(l) + 3 O2(g) ---> 2 CO2(g) + 3 H2O(l)
NEGATIVE.
The Chemical Reactants contain a GAS-MOLE's NUMBER GREATER THAN Product's One : the System-Disorder's Degrees falls down.

REACTION c)
P4(g) ---> P4(s)
NEGATIVE.
The Phenomenon sinks Vapours in order to convert them as Solid Matter : the System-Disorder's Degrees falls down.

REACTION d)
2 NaHCO3(s) ---> Na2CO3(s) + H2O(g) + CO2(g)
POSITIVE.
The Chemical Products contain a GAS-MOLE's NUMBER GREATER THAN Reactant's One : the System-Disorder's Degrees rises.

I hope this could be clear.

Answer 2

a) formation of one molecule lead chloride from 2 molecules, ability much less randomness, then there's a decrease in S; which ability delta S is unfavorable b) formation of two molecules from one molecule of CaCo3, ability greater randomness, then there's a upward push in S; which ability delta S is helpful c) formation of four molecules from 2 molecule of reactants, ability greater randomness, then there's a upward push in S; which ability delta S is helpful d)formation of one molecule from 4 molecules of reactants, ability much less randomness, then there's a decrease in S; which ability delta S is unfavorable e) formation of 8 molecules from seven molecule of reactants, ability greater randomness, then there's a upward push in S; which ability delta S is helpful f) for this reason, one molecule is reactant and one is product, however the product is a gasoline, and gasoline has greater randomness than sturdy or liquid, then there's a upward push in S; which ability delta S is helpful.

Answer 3

a - +
b - probably +
c - -
d - +