Question

If 3g of sulphur dioxide contains x molecules, how many molecules will be present in 3g of oxygen?​

Answer 1

Answer:

No. of moles of SO2 in 3g = 3g/(32 + 16×2)

n (SO2) = 3/64 moles

Molecules of SO2 in 3g = x

We know,

x = 3/64 × 6 × 10^23 molecules = 2.8 × 10^22 molecules

Now,

no. of moles of O2 = 3/16×2 =3/32 moles

No. of molecules of O2 = 3/32 × 6 × 10^23

=) 5.6 × 10^22 molecules

Note:

We could have applied Gay Lussac's law only if volume was given to us at S.T.P. But we were given mass and also no density, so we could not calculate its volume and hence couldn't apply Gay Lussac's law. I hope you understood.