In order to calculate ΔH° for a reaction which of the following sets represents numerical values that would be required?

For each of the following reactions state the signs of ∆H (enthalpy) and ∆S (entropy):

a) Fusion of ice.

b) Sublimation of CO₂

c) Vaporization of aqueous water.

d) Deposition of chlorine gas.

e) Condensation of water vapor. 

Diethyl ether (C₄H₁₀O₂, MW = 90.1 g/mol) has a boiling point of 35.6^oC and heat of vaporization of 26.7 kJ/mol. What is the change in entropy (in kJ/K) when 3.2 g of diethyl ether at 35.6^oC vaporizes at its boiling point?

2 NH₃ (g) + 2 O₂ (g) → NH₄NO₃ (s) + H₂O (l)

2 NO (g) + O₂ (g) → 2 NO₂ (g)

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

Identify sign of entropy changes for the following processes.

1) freezing water to form ice

2) ideal gas allowed to expand in a closed container at constant T

3) mixing of two gases into one container

4) NH₂ (g) (1atm) → NH₂ (g) (3 atm)

5) gas mixture transferred from larger to smaller container

Select correct statement(s) below: