Gibbs free energy (g) is a measure of the spontaneity of a chemical reaction. it is the chemical potential for a reaction, and is minimized at equilibrium. it is defined as g=h−ts where h is enthalpy, t is temperature, and s is entropy. the chemical reaction that causes magnesium to corrode in air is given by 2mg+o2→2mgo in which at 298 k δh∘rxn = −1204 kj δs∘rxn = −217.1 j/k part a what is the standard gibbs free energy for this reaction? assume the commonly used standard reference temperature of 298 k. express your answer as an integer and include the appropriate units. view available hint(s) δg∘rxnδ g r x n ∘ = nothing

ΔG° = -1123 kJ

Explanation:

Let's consider the following equation.

2 Mg + O₂ → 2 MgO

The standard Gibbs free energy (ΔG°) can be calculated with the following expression:

ΔG° = ΔH° - T.ΔS°

where,

ΔH° is the standard enthalpy of the reaction

T is the absolute temperature

ΔS° is the standard entropy of the reaction

For this reaction,

ΔG° = -1204 kJ - 298 K × (-271.1) × 10⁻³ kJ/K = -1123 kJ

By convention, ΔG° < 0 means that the reaction is spontaneous.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.