To calculate the number of molecules in 2.8g of nitrogen gas, we must first understand the relationship between mass and the number of particles (atoms or molecules) in a substance. The concept of this relationship is known as the molar mass, which is the mass of one mole of a substance.
Molar mass is defined as the mass of one mole of a substance in grams, and it is equal to the sum of the atomic masses of all atoms in a molecule. In the case of nitrogen gas, which is a diatomic molecule (N2), the molar mass is twice the atomic mass of nitrogen, as there are two nitrogen atoms in one molecule. The atomic mass of nitrogen is approximately 14.0067 amu (atomic mass units). Therefore, the molar mass of nitrogen gas is:
Molar Mass (N2) = 2 Atomic Mass (N) = 2 * 14.0067 amu = 28.0134 amu
The molar mass of nitrogen gas (N2) is 28 grams per mole, and Avogadro’s number is approximately 6.022 × 10^23 molecules per mole.
To find the number of moles in 2.8 grams of nitrogen gas, we can use the formula:
Number of moles = Mass / Molar mass
Number of moles = 2.8g / 28g/mol
Number of moles = 0.1 mol
Finally, to calculate the number of molecules, we can multiply the number of moles by Avogadro’s number:
Number of molecules = Number of moles × Avogadro’s number
Number of molecules = 0.1 mol × (6.022 × 10^23 molecules/mol)
Number of molecules = 6.022 × 10^22 molecules
Therefore, there are approximately 6.022 × 10^22 molecules in 2.8 grams of nitrogen gas.
