For the process O2(g)      2O(g), ΔH° = 498 kJ·mol –1.  What would be the predicted sign of ΔS°rxn and the conditions under which this reaction would be spontaneous?   a. ΔS°rxn is negative, and the process is spontaneous at high temperatures only.   b. ΔS°rxn is negative, and the process is spontaneous at low temperatures only.   c. ΔS°rxn is positive, and the process is spontaneous at high temperatures only.   d. ΔS°rxn is positive, and the process is spontaneous at low temperatures only.

Consider the oxidation of elemental cadmium (II) oxide.  2Cd(s)+O2 (g)--> 2CdO(s)  Using the following thermochemical data, calculate the minimu temperature in degrees Celsius at which this reaction is spontaneous.  Species  delta Hf degrees (kJ/mol)  S degrees (J/molxK) Cd(s) 0 51.8 O2 0 205.2 CdO(s) -258.4 54.8 Select the correct answer: a. 2594 degrees Celsius b. 2321 degrees Celsius  c. 1.278 degrees Celsius  d. -271.9 degrees Celsius  e. -270.6 degrees Celsius

For each of the following reactions, calculate ΔH∘rxn, ΔS∘rxn, and ΔG∘rxn at 25 ∘C. State whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 ∘C?2CH4(g)→C2H6(g)+H2(g), Calculate ΔS∘rxn at 25 ∘C. 2NH3(g)→N2H4(g)+H2(g) Calculate ΔS∘rxn at 25 ∘C. N2(g)+O2(g)→2NO(g) Calculate ΔS∘rxn at 25 ∘C. 2KClO3(s)→2KCl(s)+3O2(g) Calculate ΔS∘rxn at 25 ∘C.

From the values of ΔH and ΔS calculate the minimum temperature at which each reaction will become spontaneous. Enter "None" if the reaction is not spontaneous at any temperature. ΔH = -389 kJ/mol,  ΔS = 27.8  J/K · mol

∆Gº for the reaction, H2(g)+Br2(g)⇄2HBr(g), is -33.3 kJ. Which statement below is true?   To make this reaction go forward, 33.3 kJ must be added.   This reaction is non-spontaneous.   This reaction is spontaneous.   This reaction cannot be at equilibrium.

For each reaction, calculate ΔH°rxn, ΔS°rxn, and ΔG°rxn at 25 °C and state whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 °C?a. 2 CH4( g)------->C2H6( g) + H2( g)b. 2 NH3( g)------> N2H4( g) + H2( g)c. N2( g) + O2( g)-------->2 NO( g)d. 2 KClO3(s)-------->2 KCl(s) + 3 O2( g)

A reaction has AH°= 100 kJ/mol and AS°= 250 J/mol.K. Is the reaction spontaneous at room temperature? If not, under what temperature conditions will it become spontaneous?

The element gallium (Ga) freezes at 29.8°C its ΔHfus = 5.59 kJ/ mol. Calculate the valueof ΔS when 1.0 mol gallium freezes at its normal melting point. Is ΔS positive ornegative? Calculate the value of ΔS when 30.0 g of Ga(l) solidifies at 29.8 °C

From the values of ΔH and ΔS predict which of the following reactions would be spontaneous at 25°C. Calculate the minimum temperature at which each reaction will become spontaneous. Enter "None" if the reaction is not spontaneous at any temperature. ΔH = -75.8 kJ/mol,  ΔS = 126  J/K · mol

3. Determine the temperature (°C) range, in which the following reaction will become spontaneous. (temperatures greater, less than or equal to the given value) Fe2O3(s) + 2Al(s) → 2Fe(s) + Al203(s) AHxn = -851.5 kJ/mol ASpen = -375.2 J/mol K %3D