Check the following statement is correct or not ?

Answer

To determine whether the statement "spontaneous adsorption of gases on solid surface is an exothermic process as entropy decreases during the adsorption" is correct, we can analyze the thermodynamic principles involved.

### Step 1: Understand Spontaneous Processes
A spontaneous process is one that occurs without needing to be driven by an external force. For a process to be spontaneous, the change in Gibbs free energy (ΔG) must be negative.

**Hint:** Recall that a negative ΔG indicates a spontaneous reaction.

### Step 2: Analyze Entropy Change
In the case of gas adsorption on a solid surface, the gas molecules transition from a more disordered state (gas phase) to a more ordered state (adsorbed on the surface). This results in a decrease in entropy (ΔS < 0).

**Hint:** Remember that a decrease in randomness corresponds to a decrease in entropy.

### Step 3: Apply the Gibbs Free Energy Equation
The relationship between Gibbs free energy, enthalpy change (ΔH), and entropy change is given by the equation:
\[ \Delta G = \Delta H - T \Delta S \]
Here, T is the temperature in Kelvin.

**Hint:** This equation helps us relate the changes in enthalpy and entropy to the spontaneity of the process.

### Step 4: Determine the Signs of ΔG and ΔS
Since the adsorption process is spontaneous, ΔG must be negative. We have established that ΔS is negative (due to decreased randomness).

**Hint:** Consider how the signs of ΔG and ΔS affect the overall equation.

### Step 5: Analyze the Implications for ΔH
If ΔS is negative, then the term \( -T \Delta S \) becomes positive (since T is always positive). Therefore, for ΔG to remain negative (spontaneous), ΔH must also be negative (exothermic process).

**Hint:** A negative ΔH indicates that the process releases heat, which is characteristic of exothermic reactions.

### Conclusion
Since both ΔG is negative and ΔH is negative, we conclude that the spontaneous adsorption of gases on solid surfaces is indeed an exothermic process. Thus, the statement given is correct.

**Final Answer:** The statement is correct.