Question

Calculate the number of electrons, protons and neutrons present in 3.2 gram of oxygen gas.

Answer 1

Molar mass of O₂ gas = 32 g/mol

Therefore,

No. of moles in 3.2g of O₂ = 3.2/32 = 0.1

Now, number of molecules in 1 mole of O₂ = 6.022 x 10²³

Therefore, no. of molecules in 0.1 mole of O₂ = 0.1 x 6.022 x 10²³ = 6.022 x 10²².

One O₂ molecule contains 16 electons, 16 protons & 16 neutrons.

Therefore, number of electons = number of protons = number of neutrons in 3,2 g of O2 = 16 x 6.022 x 10²²

= 96.352 x 10²²

= 9.6352 x 10²³.