Question

Number of oxygen atoms present in 4g of dioxygen

Answer 1

Dioxygen=O2(molecular mass=32)
Number of moles=given mass/molecular mass=4/32=1/8=0.125
Number of molecules =0.125x 6.022x10²³.
No. Of atoms=2x no. Of molecules (O2-atomicity is 2)=2x0.125x6.022x10²³.