Pressure and Concentration Relationship

Introduction:
The relationship between pressure and concentration of a gas at constant temperature is described by the ideal gas law. According to the ideal gas law, the pressure of a gas is directly proportional to its concentration when temperature is held constant.

Explanation:
1. Ideal Gas Law:
The ideal gas law is a mathematical relationship between the pressure (P), volume (V), temperature (T), and number of moles (n) of a gas. It can be expressed as:
PV = nRT

Where:
P = pressure of the gas
V = volume of the gas
n = number of moles of the gas
R = ideal gas constant
T = temperature in Kelvin

2. Constant Temperature:
The given statement states that the temperature is constant. When temperature is held constant, the ideal gas law equation can be simplified to:
P ∝ n

This means that pressure is directly proportional to the number of moles of the gas.

3. Concentration and Number of Moles:
The concentration of a gas can be defined as the amount of gas present in a given volume. It is usually expressed in terms of moles per liter (mol/L) or molar concentration. The concentration of a gas is directly related to the number of moles of the gas.

4. Pressure and Concentration:
Since the number of moles of a gas is directly proportional to its concentration, and the pressure of a gas is directly proportional to the number of moles, it follows that the pressure of a gas is directly proportional to its concentration when temperature is held constant.

Conclusion:
In conclusion, at constant temperature, the pressure of a gas is directly proportional to its concentration. This relationship can be explained by the ideal gas law, where pressure is directly proportional to the number of moles of the gas, and the concentration of a gas is directly related to the number of moles.