19. Chemical Thermodynamics

Select correct statement(s) below:

a) gaseous CO₂ has higher entropy in 2 L container compared to in 5 L container

b) N₂O (g) contains higher standard molar entropy then HI (g)

c) NaHCO₃ (aq) + HC₂H₃O₂ (aq) → NaC₂H₃O₂ (aq) + H₂O (l) + CO₂ (g) has a negative ∆S

d) evaporation of water at 100 °C involves greater ∆S than evaporation at 112 °C

Which reaction is most likely to have a positive ∆S of reaction?

a) SiO₂ (s)  +  3 C (s)  →  SiC (s)  +  2 CO (g)

b) 6 CO₂ (g)  +  6 H₂O (g)  → C₆H₁₂O₆ (s)  +  6 O₂ (g)

c) CO (g)  +  Cl₂ (g)  → COCl₂ (g)

d) 3 NO₂ (g)  +  H₂O (l)  → 2 HNO₃ (l)  +  NO (g)

Entropy is the measure of ________ in a system.

Predict the sign of ∆S in the system for each of the following processes:

a) Ag⁺ (aq) + Br ^- (aq) → AgBr (s)

b) CI₂ (g) → 2 CI ^- (g)

c) CaCO₃ (s) → CaO (s) + CO₂ (g)

d) Pb (s) at 50^°C → Pb (s) at 70^°C