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In a chemical reaction, the standard free energy change (ΔG°') is calculated to be -3.67 cal/mol. What can be said of the chemical reaction?

A. Reactants predominate over products at equilibrium under standard conditions.
B. The reaction is not spontaneous under standard conditions.
C. The reaction is at equilibrium under standard conditions.
D. There can be no reaction.
E. The reaction is spontaneous under standard conditions.

User TeamDman
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Final answer:

The chemical reaction with a standard free energy change (ΔG°') of -3.67 cal/mol is spontaneous under standard conditions, meaning that the products will be favored over the reactants at equilibrium.

Step-by-step explanation:

The standard free energy change (ΔG°') of a chemical reaction being -3.67 cal/mol indicates the reaction under standard conditions. Here, a negative value of ΔG°' signifies that the reaction is spontaneous under standard conditions, which means that it will proceed without the need for additional energy. In simple terms, the products will be favored over the reactants at equilibrium, which corresponds to option E: The reaction is spontaneous under standard conditions.

It is important to note that 'spontaneous' does not mean that the reaction occurs instantly or completes entirely. It merely implies that the equilibrium mixture will contain a larger proportion of products than reactants. The standard conditions usually refer to a pressure of 1 atm, a temperature of 25°C (298 K), and in biological systems, a pH of 7.0.

The value of the standard free energy change is also related to the equilibrium constant (Keq) of the reaction, as described by the Boltzmann equation: ΔG° = -RTln Keq. In this formula, R is the gas constant, T is the temperature in kelvins, and Keq is the equilibrium constant. When ΔG° is negative, the reaction is exergonic and releases free energy, making it spontaneous.

User Amritpal Nagra
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