2H2 (g)+O2(g)2H2O(1) Hsystem--483kJ Part B-Predicting the entropy change for the

Question

2H2 (g)+O2(g)2H2O(1) Hsystem--483kJ Part B-Predicting the entropy change for the system, 5,ystem, from the balanced equation Positive Predicting the entropy change for the system, ASsystem, from the balanced equation: Negative Isas,ystem positive or negative? Is this entropy change a driving force for spontaneity? Yes No Predicting how the enthalpy change for the system, AHsystem, affects ASsurr Based on the sign of AHsystem, is this reaction endothermic or exothermic? Does the temperature of the surroundings increase or decrease? Is ASsurroundings positive or negative? Is this enthalpy change a driving force for spontaneity? Endothermic Exothermic Increase Decrease Consider the signs of as you determined above and that Suniverse-assystem + assurroundings aystem Given that this reaction is spontaneous at 298K, which value should be larger in magnitude at 298K, ASsystem or ASsurroundings? ASsurroundings

Explanation / Answer

Q1

a)

dS --> the system has 2+1 = 3 mol of gas, they form 2 mol fo liquid,

liquid entropy <<< gas entropy, so this must be NEGATIVE

b)

NO, since entropy is negative, this is not driving towards "spontaneous" process

Q2

a)

dHsystem --> is negative, which implies energy los, that is, it release heat, exothermic

b)

T must increase, since Heat is released

c)

dS --> -dH

then, the entropy of surroundings must be increasing

d)

this is in fact a driving force, since -dH value will favour -dG

Q3

given dH, dS value

dSuniverse = dSsystem - dHsystem/Tsurr

dS uinvierse will beposivie

therefore, it is possible

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.