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Fill in the blanks by putting appropriate choices. During adsorption there is _______ in enthalpy and _______ in the entropy of a system by adsorption is a spontaneous process and thus `DeltaG` must be ________. Rate of physisorption ________ with increase in pressure.

A

decrease, decrease, negative , increase

B

increase, increase , positive , decrease

C

decrease, increase, negative , decrease

D

increase, decrease, positive , increase

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To solve the question step by step, we will analyze each part of the statement and fill in the appropriate choices. ### Step 1: Understanding the first blank - The first part of the statement is: "During adsorption there is _______ in enthalpy." - During the process of adsorption, the molecules of the adsorbate are attracted to the surface of the adsorbent. This attraction leads to a more stable system, which generally results in a decrease in enthalpy. - **Answer for the first blank:** Decrease ### Step 2: Understanding the second blank - The second part of the statement is: "and _______ in the entropy of a system." - Entropy is a measure of disorder in a system. When molecules adsorb onto a surface, they become more ordered due to the interactions with the surface, leading to a decrease in entropy. - **Answer for the second blank:** Decrease ### Step 3: Understanding the third blank - The third part of the statement is: "by adsorption is a spontaneous process and thus `DeltaG` must be ________." - For a process to be spontaneous, the change in Gibbs free energy (ΔG) must be negative. This indicates that the process can occur without external energy input. - **Answer for the third blank:** Negative ### Step 4: Understanding the fourth blank - The fourth part of the statement is: "Rate of physisorption ________ with increase in pressure." - Physisorption is the physical adsorption of molecules onto a surface. According to the principles of adsorption, as pressure increases, the rate of physisorption also increases because more adsorbate molecules are available to interact with the adsorbent surface. - **Answer for the fourth blank:** Increase ### Final Answers Putting it all together, the filled statement is: "During adsorption there is **Decrease** in enthalpy and **Decrease** in the entropy of a system by adsorption is a spontaneous process and thus `DeltaG` must be **Negative**. Rate of physisorption **Increase** with increase in pressure."
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