For an ideal gas, number of moles per litre in terms of its pressure P, gas constant R and temperature T is

Options

A. PT / R
B. P / RT
C. PRT
D. RT / P

Explanation

To find the number of moles per liter (n/V) of an ideal gas in terms of its pressure (P), gas constant (R), and temperature (T), we can follow these steps:

### Step-by-Step Solution:

1. **Start with the Ideal Gas Law**:
The ideal gas law is given by the equation:
\[ PV = nRT \]
where:
- \(P\) = Pressure of the gas
- \(V\) = Volume of the gas
- \(n\) = Number of moles of the gas
- \(R\) = Universal gas constant
- \(T\) = Temperature of the gas in Kelvin

2. **Rearrange the Ideal Gas Law**:
We want to express the number of moles per liter, which is \(n/V\). To do this, we can rearrange the ideal gas equation:
\[ n = \frac{PV}{RT} \]

3. **Express Number of Moles per Liter**:
To find \(n/V\), we divide both sides of the equation by \(V\):
\[ \frac{n}{V} = \frac{P}{RT} \]

4. **Final Expression**:
Thus, the number of moles per liter (n/V) in terms of pressure (P), gas constant (R), and temperature (T) is:
\[ \frac{n}{V} = \frac{P}{RT} \]

### Conclusion:
The correct expression for the number of moles per liter of an ideal gas is:
\[ \frac{n}{V} = \frac{P}{RT} \]