What is the molar mass of nitrogen gas (Nâ‚‚)?
The Correct Answer and Explanation is:
The molar mass of nitrogen gas (N₂) is 28.02 grams per mole (g/mol).
Explanation:
Nitrogen gas exists naturally as a diatomic molecule, which means that each molecule of nitrogen gas is made up of two nitrogen atoms bonded together (N₂). To calculate the molar mass of N₂, we must determine the atomic mass of a single nitrogen atom and then multiply by 2.
The atomic mass of one nitrogen atom is approximately 14.01 g/mol. This value comes from the periodic table and represents the average mass of all nitrogen isotopes found in nature.
Since nitrogen gas contains two nitrogen atoms per molecule, we calculate the molar mass as:
14.01 g/mol × 2 = 28.02 g/mol
So, the molar mass of N₂ is 28.02 g/mol.
Why is this important?
The concept of molar mass is fundamental in chemistry. It allows scientists to convert between the mass of a substance and the number of moles, which is a count of how many particles (in this case, molecules) are present.
For example, if you have 28.02 grams of nitrogen gas, that amount contains exactly one mole of N₂ molecules, or 6.022 × 10²³ molecules (Avogadro’s number). This conversion is essential when performing chemical reactions, as balanced chemical equations use moles to show the proportions of reactants and products.
In practical terms, knowing the molar mass helps in measuring and preparing chemical substances accurately in laboratories or industrial processes. For gases like nitrogen, it also assists in calculations involving the ideal gas law, which relates pressure, volume, temperature, and number of moles of a gas.
Understanding and using molar mass is key to mastering quantitative chemistry.
