Solved: CHEMISTRY Question for NEET | Sushrut

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NEET CHEMISTRYMedium

The maximum number of molecules is present in:

A

5L of N₂ gas at STP

B

0.5 g of H₂ gas

C

10g of O₂ gas

D

15 L of H₂ gas at STP

Step-by-Step Solution

Identify the Principle: The number of molecules is directly proportional to the number of moles ( $n$ ).

For gases at STP (Standard Temperature and Pressure), $n = \frac{\text{Volume (L)}}{22.4}$ .
For mass, $n = \frac{\text{Mass (g)}}{\text{Molar Mass (g/mol)}}$ .

Calculate Moles for each option:

Option 1: $5\text{ L}$ of $N_2$ at STP. $n = \frac{5}{22.4} \approx 0.223 \text{ mol}$
Option 2: $0.5\text{ g}$ of $H_2$ . Molar mass of $H_2 = 2\text{ g/mol}$ . $n = \frac{0.5}{2} = 0.25 \text{ mol}$
Option 3: $10\text{ g}$ of $O_2$ . Molar mass of $O_2 = 32\text{ g/mol}$ . $n = \frac{10}{32} = 0.3125 \text{ mol}$
Option 4: $15\text{ L}$ of $H_2$ at STP. $n = \frac{15}{22.4} \approx 0.67 \text{ mol}$

Conclusion: Option 4 has the highest number of moles ( $0.67$ ), therefore it contains the maximum number of molecules.

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Solved: CHEMISTRY Question for NEET | Sushrut