calculate the number of molecules in 1ml of O2 at STP
At STP 1 mole of any gas occupies 22.4 L of volume.
For O2, the molar mass = 32 g/ mol
This means, 32 g or 1 mole of oxygen gas occupies a volume of = 22.4 L
1 L = 1000 mL
This implies,
22400 mL of volume is occupied by = 1 mol
1 mL of volume is occupied by = 1/ 22400 mol
= 4.46 10-5 mol
As, 1 mol = 6.022 1023
Therefore, 1 mL of volume is occupied by = 4.46 10-5 6.022 1023 molecules.
= 26.85 1018 molecules
= 2.685 1019 molecules
Hence, number of molecules present in 1 mL of oxygen gas is 2.685 1019
For O2, the molar mass = 32 g/ mol
This means, 32 g or 1 mole of oxygen gas occupies a volume of = 22.4 L
1 L = 1000 mL
This implies,
22400 mL of volume is occupied by = 1 mol
1 mL of volume is occupied by = 1/ 22400 mol
= 4.46 10-5 mol
As, 1 mol = 6.022 1023
Therefore, 1 mL of volume is occupied by = 4.46 10-5 6.022 1023 molecules.
= 26.85 1018 molecules
= 2.685 1019 molecules
Hence, number of molecules present in 1 mL of oxygen gas is 2.685 1019