Answer;
= 18.24
Explanation;
The ratio of N and O in the formula NO2 IS 1:2
Mass of nitrogen gas is 0.500 g
Moles of nitrogen will be;
= 0.500/16 = 0.03125 moles
Therefore;
The moles of Oxygen from the ratio will be;
= 0.03125 × 2 = 0.0625 moles
But; 0.0625 moles is equal to 1.140 g of Oxygen
The atomic number (mass in 1 mole) will be;
= 1.140 /0.0625
= 18.24
Thus the atomic number of Oxygen from the data is 18.24
The balanced chemical equation for the given reaction is:
N₂ + 2O₂ → 2NO₂
According to the given balanced equation, 2 moles of O₂ combines with 1 mole of O₂
Given, Mass of O₂ = 1.140 g
Atomic mass of O = 16 amu
Molar mass of O₂ = 16 x 2 = 32 g/mol
Now to calculate the moles of N₂:
1.14 g of O₂ x (1 mole of O₂/ 32 g of O₂) x (1 mol of N₂/ 2 mol O₂) = 0.0178 mol of N₂
Molar mass = mass/ moles
Given, Mass of N₂ = 0.500 g
Molar mass of N₂ = 0.500 g / 0.0178 mol = 28 g/mol
Atomic mass of N = 28/2 = 14 amu
Therefore, the atomic mass of N is 14 amu
