Answer:
a )0.05 moles of O₂
b) 1.1207 dm³
c) 0.3× 10²³ atoms of oxygen
d) 1.6 g
Explanation:
Given data:
Number of molecules of O₂ = 3.01 × 10²² molecules
Number of moles of O₂ = ?
Volume of oxygen at ATP = ?
Number of oxygen atoms = ?
Mass of oxygen = ?
Solution:
The given problem will solve by using Avogadro number.
"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance". The number 6.022 × 10²³ is called Avogadro number.
Moles of oxygen:
1 mole = 6.022 × 10²³ molecules
3.01 × 10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.05 moles of O₂
Number of atoms of oxygen:
1 mole = 6.022 × 10²³ atoms
0.05 mol × 6.022 × 10²³ atoms /1 mol
0.3× 10²³ atoms of oxygen
Volume of oxygen:
1 mole of oxygen at STP occupy 22.414 dm³
0.05 mol × 22.414 dm³ / 1mol
1.1207 dm³
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.05 mol × 32 g/mol
Mass = 1.6 g
