Question

calculate the number of molecule in 4g of oxygen ????? please explain it

Answer 1

molecular mass of one molecule of oxygen (O2) = 32u

Mass=4g

Therefore, no. of moles = mass÷molecular mass

Hence, moles = 0.125

1 moles of oxygen contains 6.022 X 10^23 molecules (Avagadro's no. )

Therefore, 0.125 moles contain
$0.125 \times 6.022 \times {10}^{23}$
= 0.75275 X 10^23 molecules of O2