Out of the three states of matter, only the gases have most of the physical properties common. They neither have definite shapes nor volumes. Upon mixing they form homogeneous mixture irrespective of their nature and can also be compressed on applying pressure. In addition to these, the gases obey different gas laws such as boyle's Law, Charles's Law, Dalton's Law of partial pressures, Graham's Law of diffusion etc. Based upon these laws, ideal gas equation `PV = nRT` has been derived.
4-4 g of a gas at STP occupies a volume of `2.224` L. The gas can be :

Options

A. `O_(2)`
B. `CO`
C. `NO_(2)`
D. `CO_(2)`

Explanation

To solve the problem, we need to determine which gas has a molar mass of 44 g/mol based on the information provided. Here’s a step-by-step solution:

### Step 1: Understand the Given Information
We are given that 4.4 g of a gas occupies a volume of 2.224 L at standard temperature and pressure (STP). At STP, 1 mole of an ideal gas occupies 22.4 L.

### Step 2: Calculate the Number of Moles of the Gas
Using the formula for the number of moles (n):
\[ n = \frac{\text{Volume}}{22.4 \, \text{L}} \]
Substituting the given volume:
\[ n = \frac{2.224 \, \text{L}}{22.4 \, \text{L}} = \frac{1}{10} = 0.1 \, \text{moles} \]

### Step 3: Use the Molar Mass Formula
The molar mass (M) can be calculated using the formula:
\[ M = \frac{\text{mass}}{n} \]
Substituting the mass and the number of moles we just calculated:
\[ M = \frac{4.4 \, \text{g}}{0.1 \, \text{moles}} = 44 \, \text{g/mol} \]

### Step 4: Identify the Gas Based on Molar Mass
Now, we need to identify which gas has a molar mass of 44 g/mol. We can check the molar masses of the given options:
1. **O2 (Oxygen)**: Molar mass = 16 g/mol × 2 = 32 g/mol
2. **CO (Carbon Monoxide)**: Molar mass = 12 g/mol + 16 g/mol = 28 g/mol
3. **NO2 (Nitrogen Dioxide)**: Molar mass = 14 g/mol + 16 g/mol × 2 = 46 g/mol
4. **CO2 (Carbon Dioxide)**: Molar mass = 12 g/mol + 16 g/mol × 2 = 44 g/mol

### Step 5: Conclusion
The gas that matches the calculated molar mass of 44 g/mol is **Carbon Dioxide (CO2)**.

Thus, the answer is **CO2**.

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