Dynamic equilibrium between liquid and gas is established when . a. the vapor pressure of the liquid equals the external pressureb. the liquid and vapor are at the same temperaturec. a liquid vaporizes and condenses at the same rated. the liquid is entirely evaporated

The correct answer is option c. "a liquid vaporizes and condenses at the same rate"

Explanation:

In chemistry, dynamic equilibrium is defined as a state where the reaction rate of a forward reaction is equal to the reaction rate of the backward reaction. In this case, the reactions that participate in the system are the vaporization of a liquid and the condensation of a gas. Therefore, dynamic equilibrium is established when a liquid vaporizes and condenses at the same rate.

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