Consider an ideal gas contained in a vessel If the intermolecular interaction suddenly begins to act which of the following will happen ?.

Options

A. Pressure decreases
B. Pressure increases
C. Pressure remains unchanged
D. Gas collapses

Explanation

To solve the question regarding the behavior of an ideal gas when intermolecular interactions suddenly begin to act, we can follow these steps:

### Step 1: Understanding Ideal Gas Behavior
An ideal gas is defined as a gas that follows the ideal gas law, which states that:
\[ PV = nRT \]
where:
- \( P \) = pressure
- \( V \) = volume
- \( n \) = number of moles
- \( R \) = universal gas constant
- \( T \) = temperature

In an ideal gas, there are no intermolecular forces acting between the gas molecules.

**Hint:** Recall the characteristics of an ideal gas and the ideal gas law.

### Step 2: Introduction of Intermolecular Interactions
When intermolecular interactions suddenly begin to act, the gas will no longer behave as an ideal gas. Instead, it will start to exhibit behavior similar to that of a real gas. In real gases, intermolecular forces (attractive or repulsive) come into play, affecting the pressure and volume of the gas.

**Hint:** Consider how intermolecular forces influence the behavior of gases.

### Step 3: Analyzing the Effect on Pressure
The presence of intermolecular attractions means that gas molecules will exert less pressure on the walls of the container than they would if they were ideal. This is because some of the energy that would contribute to pressure is used in overcoming these intermolecular forces.

In the case of a real gas, the modified equation that accounts for intermolecular forces is:
\[ P + \frac{a}{V^2} (n^2) = \frac{nRT}{V - nb} \]
where \( a \) is a constant that accounts for the attractive forces between molecules.

**Hint:** Think about how the addition of intermolecular forces alters the pressure exerted by the gas.

### Step 4: Conclusion
Since the intermolecular forces are now acting, the pressure exerted by the gas will decrease compared to the pressure predicted by the ideal gas law. Thus, if intermolecular interactions suddenly begin to act, the pressure of the gas will start to decrease.

**Hint:** Summarize the effects of intermolecular forces on gas pressure and behavior.

### Final Answer
If the intermolecular interaction suddenly begins to act on an ideal gas contained in a vessel, the pressure of the gas will start to decrease.