The volumes of gases A, B, C and D are in the ratio, 1:2:2:4 under the same conditions of temperature and pressure.
Which sample of gas contains the maximum number of molecules?

Answer

To determine which sample of gas contains the maximum number of molecules, we can follow these steps:

### Step 1: Understand the Volume Ratio
The volumes of gases A, B, C, and D are given in the ratio of 1:2:2:4. This means:
- Volume of gas A = 1 unit
- Volume of gas B = 2 units
- Volume of gas C = 2 units
- Volume of gas D = 4 units

### Step 2: Apply Avogadro's Law
According to Avogadro's Law, at the same temperature and pressure, equal volumes of gases contain an equal number of molecules. Therefore, the number of molecules is directly proportional to the volume of the gas.

### Step 3: Compare the Volumes
From the volume ratios:
- Gas A has 1 unit of volume.
- Gas B has 2 units of volume.
- Gas C has 2 units of volume.
- Gas D has 4 units of volume.

### Step 4: Identify the Maximum Volume
Among the gases, gas D has the largest volume (4 units). Since the number of molecules is proportional to the volume, gas D will contain the maximum number of molecules.

### Conclusion
Gas D contains the maximum number of molecules.

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