How do I find out if a reaction is spontaneous or not spontaneous?

A chemical engineer is studying the two reactions shown in the table below. In each case, he fills a reaction vessel with some mixture of the reactants and products at a constant temperature of 15.0 °C and constant total pressure. Then, he measures the reaction enthalpy AH and reaction entropy AS of the first reaction, and the reaction enthalpy AH and reaction free energy AG of the second reaction. The results of his measurements are shown in the table. Complete the table. That is, calculate AG for the first reaction and AS for the second. (Round your answer to zero decimal places.) Then, decide whether, under the conditions the engineer has set up, the reaction is spontaneous, the reverse reaction is spontaneous, or neither forward nor reverse reaction is spontaneous because the system is at equilibrium. 6C(s) + 6H₂(g) + 30₂(g) 2Al(s) + 3H₂O(g) C6H₁2O6 (s) Al₂O3 (s) + 3H₂(g) AH = -1237. kJ AS-4214. AG = KJ Which is spontaneous? this reaction the reverse reaction neither ΔΗ = -951. kJ…

Classify each of the reactions according to one of the four reaction types summarized in the table below. Reaction Spontaneous Process? Туре ΔΗ' (system) AS (system) (Standard Conditions) 1 Exothermic, 0 Spontaneous at all temperatures. AS (universe) > 0. Exothermic, 0 Positive, > 0 Depends on relative magnitudes of AH and AS". Spontaneous at higher temperatures. 3 Endothermic, > 0 Negative, < o Not spontaneous at any temperature. AS° (universe) < 0. 4 C6 H12O6 (s) + 6 02 (g) → 6 CO2 (g) + 6 H2O(l) a. A,H° = -673 kJ/mol-rxn A,S° = 60.4 J/K · mol-rxn O Spontaneous at all temperatures. O Spontaneous at lower temperatures. O Spontaneous at higher temperatures. ONot spontaneous at any temperature. b. ВаО(s) + C(graphite) — Ba(s) + СО(g) A,H° = 437.6 kJ/mol-rxn A,S° = 184.9 J/K· mol-rxn OSpontaneous at all temperatures. O Spontaneous at lower temperatures. O Spontaneous at higher temperatures. ONot spontaneous at any temperature.

A certain chemical reaction has a negative value for Δ????. What must be true? The reverse chemical reaction is spontaneous The reaction takes place reversibly The chemical reaction is spontaneous The reaction takes place irreversible Please explain, to my understanding when entropy of the universe is (-) it is equal to zero. I must be missing something or it's not clicking to what I have learned.