Exam 16: Thermodynamics: Entropy, free Energy, and Equilibrium

The figure represents the spontaneous deposition of iodine in which iodine vapor,I₂(g),becomes crystalline iodine solid I₂(s): I₂(g): → I₂(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

At high temperatures boron carbide vaporizes according to the equation B₄C(s)⇌ 4 B(g)+ C(s) Which equation describes the relationship between ΔG° and ΔG for this reaction?

For the reaction N₂(g)+2 O₂(g)→ 2 NO₂(g),ΔH° = 66.4 kJ/mol and ΔS° = -121.5 J/K.ΔS_total for this reaction is ________ J/K,and the reaction is ________ (spontaneous,nonspontaneous)at 25°C.

In figure (1)below oxygen molecules,represented by unshaded spheres,and chlorine molecules,represented by shaded spheres,are in separate compartments.Figure (2)shows the equilibrium state of the system after the stopcock separating the two compartments is opened.Assuming the oxygen and the chlorine behave as ideal gases,what are the signs (+,-,or 0)of ΔH,ΔS,and ΔG for this process?

Which statement is true about the formation of CaCO₃(s)from CaO(s)and CO₂(g)at 1.00 atm? CaO(s)+ CO₂(g)→ CaCO₃(s)ΔH° = -178.7 kJ and ΔS° = -150.4 J/K

When equilibrium is reached at constant temperature and pressure,

Other than only PV work,what reaction conditions must be satisfied for the sign of ΔG to be used as a criterion for spontaneity?

Standard molar entropies,S°,in J/Kmol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K. S(s,rhombic)+ O₂(g)→ SO₂(g) 31.8 205.0 248.1

The entropy of water at 25° is ________ than the entropy of water at 35°C.

According to the second law of thermodynamics,all reactions proceed spontaneously in the direction that increases the entropy of the

The most commonly used white pigment is titanium white,which is titanium(IV)oxide,TiO₂.Titanium white can be formed from TiCl₄ as shown in the reaction below. TiCl₄(l)+ 2 H₂O(l)→ TiO₂(s)+ 4 HCl(g) If ΔH° = 61.9 kJ/mol and ΔS° = 405.4 J/K,what are ΔS_surr and ΔS_total for this reaction at 25°C?

Which of the following processes is spontaneous?

The entropy change associated with the expansion of one mole of an ideal gas from an initial volume of V_i to a final volume of V_f at constant temperature is given by the equation,ΔS = R ln (V_f/V_i).What is the entropy change associated with the expansion of three moles of an ideal gas from an initial volume of V_i to a final volume of V_f at constant temperature?

Consider the reaction 2A(g)⇌ A₂(g).The following pictures represent two possible initial states and the equilibrium state of the system. -For initial state 1 what is the relationship between the reaction quotient,Q_p,and the equilibrium constant,K_p?

A reaction has ΔG° = + 21.5 kJ/mol,ΔH° = + 25.0 kJ/mol,and ΔS° = + 15.0 J/mol∙K can become spontaneous at a temperature of ________ K.

Calculate the standard free energy change at 25°C for the reaction 2 NO(g)+ O₂(g)→ 2 NO₂(g).

Which of the following statements is not true?

Standard molar entropies,S°,in J/Kmol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K. 2 SO₂(g)+ O₂(g)→ 2 SO₃(g) 248.1 205.0 256.6

A 1.0 mole sample of gas at STP has a ________ entropy than 1.0 mole of gas at 273 K and 835 mm Hg.

Standard molar entropies,S°,in J/K∙mol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K. CH₄(g)+ 2 O₂(g)→ CO₂(g)+ 2 H₂O(l) 186.2 205.0 213.6 69.9