The question asks for the definition of a state of dynamic equilibrium. Understanding the term "dynamic" is key here, as it implies ongoing activity rather than a complete cessation of processes.
B) The forward and reverse processes occur at equal rates, so the observable properties remain constant. This accurately describes dynamic equilibrium. The processes are still happening (dynamic), but because they are happening at the same rate in opposite directions, there is no net change, and macroscopic properties appear constant (equilibrium).
The question describes a system of water and its vapour in a closed vessel at a fixed temperature, asking about the condition for equilibrium. This scenario relates to phase equilibrium, specifically liquid-vapour equilibrium. Equilibrium in such a dynamic system is achieved when opposing processes occur at equal rates.
Correct Option: D) The rate of evaporation equals the rate of condensation. This statement accurately defines the condition for dynamic equilibrium between a liquid and its vapour in a closed system at a fixed temperature. At equilibrium, the macroscopic properties of the system (like vapour pressure, liquid level) remain constant, even though microscopic processes continue.
The question asks for the specific term describing the pressure exerted by the vapor of a liquid when it is in equilibrium with its own liquid at a given temperature. We need to identify the correct scientific term from the given options.
Correct Option: A) Vapour pressure is the pressure exerted by the vapor of a liquid when it is in equilibrium with its own liquid at a given temperature. This is a fundamental concept in physical chemistry.
This question asks about the equilibrium state between a solid and its saturated solution. This is a classic example of dynamic equilibrium, where opposing processes occur at equal rates.
This statement accurately describes the state of dynamic equilibrium between a solid and its saturated solution. At equilibrium, the forward process (dissolution) and the reverse process (crystallisation) occur at the same rate, leading to no net change in the macroscopic properties of the system.
This is incorrect. In a saturated solution at equilibrium, both dissolution and crystallisation are ongoing processes. If only dissolution occurred, the solution would never reach saturation, and the solid would eventually disappear (unless it's insoluble).
This is incorrect. Once equilibrium is reached, the amount of undissolved solid remains constant because the rate of dissolution equals the rate of crystallisation. There is no net increase or decrease in the solid amount.
This is incorrect. The concentration of the solute in a saturated solution reaches a maximum value (the solubility limit) and then remains constant at equilibrium. It does not increase indefinitely because the rate of crystallisation balances the rate of dissolution.
The question asks about Henry's law, which describes the solubility of a gas in a liquid. We need to identify the statement that correctly represents this law at a given temperature.
D) The mass of a gas dissolved per unit volume of solvent is proportional to the pressure of the gas above the solvent
This statement directly reflects Henry's law. The "mass of a gas dissolved per unit volume of solvent" is a measure of solubility or concentration (\(C\)). The statement says this is proportional to the "pressure of the gas above the solvent\
The question asks for a common characteristic feature of all general physical equilibrium processes. We need to evaluate each option based on the fundamental principles of chemical and physical equilibria.
B) Equilibrium is possible only in a closed system, and it can be approached from either direction.
This statement accurately describes two fundamental characteristics of equilibrium. For a system to reach a stable equilibrium, it must be closed, meaning no matter can enter or leave. This ensures that the total amount of substances involved remains constant, allowing the forward and reverse rates to balance. Furthermore, a true equilibrium state is independent of the direction from which it is approached. Whether you start with reactants or products, the system will eventually settle into the same equilibrium composition under the same conditions.