The mass of 0-5 mole of N₂ gas is

Correct option is B

Correct Answer: B (14 g)

Explanation:
The mass of a substance is calculated using the formula:
Mass = Number of moles × Molar mass

• The molar mass of nitrogen gas (N₂) is 28 g/mol.
• Given number of moles = 0.5 mole.

Thus,
Mass = 0.5 × 28 = 14 g.

• Option A (7 g): Incorrect, as it does not match the calculation.
• Option C (21 g): Incorrect, as it overestimates the mass.
• Option D (28 g): Incorrect, as it represents the mass of 1 mole, not 0.5 mole.

Key Facts:
● Molar mass of N₂: The sum of two nitrogen atoms (14 × 2 = 28 g/mol).
● Mole concept: 1 mole of any substance contains 6.022 × 10²³ molecules.
● Applications of N₂: Widely used in industries for creating inert atmospheres and as a refrigerant in liquid form.