A gas behaves more closely as an ideal gas at (a)low pressure and low temperature. (b)low pressure and high temperature (c) high pressure and low temperature (d) high pressure and high temperature

Options

A. (a)low pressure and low temperature
B. (b)low pressure and high temperature
C. (c)high pressure and low temperature
D. (d)high pressure and high temperature.

Answer

To determine the conditions under which a gas behaves more closely as an ideal gas, we can analyze the options provided:

### Step 1: Understanding Ideal Gas Behavior
An ideal gas is a theoretical gas composed of many particles that are in constant random motion and do not interact with each other except during elastic collisions. The behavior of real gases deviates from ideal gas behavior under certain conditions.

### Step 2: Analyzing the Options
1. **(a) Low pressure and low temperature**: At low pressure, the gas molecules are far apart, which is favorable for ideal gas behavior. However, at low temperature, the kinetic energy of the molecules is also low, leading to increased intermolecular forces, which makes the gas deviate from ideal behavior.

2. **(b) Low pressure and high temperature**: Low pressure means the gas molecules are far apart, reducing intermolecular interactions. High temperature increases the kinetic energy of the molecules, minimizing the effect of intermolecular forces. This combination is favorable for ideal gas behavior.

3. **(c) High pressure and low temperature**: High pressure forces gas molecules closer together, increasing intermolecular interactions. Low temperature decreases kinetic energy, which can lead to further deviations from ideal behavior due to increased attraction between molecules.

4. **(d) High pressure and high temperature**: While high temperature may increase kinetic energy, high pressure leads to closer proximity of molecules, which increases interactions and deviations from ideal behavior.

### Step 3: Conclusion
From the analysis, the best conditions for a gas to behave more closely as an ideal gas are found in option **(b) low pressure and high temperature**.

### Final Answer:
(b) low pressure and high temperature

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