3. Calculate the number of moles and mass in
gram_of_1 x 10^20mdecules of Nz gas
.

0.17×10⁻³ mol

Mass = 0.00476 g

Explanation:

Given data:

Number of molecules of N₂ = 1 ×10²⁰ molecules

Number of moles of N₂ = ?

Mass in gram of N₂ = ?

Solution:

1 mole of any substance contain 6.022×10²³ molecules

1 ×10²⁰ molecules× 1 mol /6.022×10²³ molecules

0.17×10⁻³ mol

Mass in gram:

Mass = number of moles × molar mass

Mass = 0.17×10⁻³ mol × 28 g/mol

Mass = 4.76×10⁻³  g

Mass = 0.00476 g