Question

Calculate number of moles and mlecules present in 0.032 mg of mithene (C=12 H=1)

Answer 1

I think you mean "methane"? If it is...
Methane's chemical formula is CH4. To get the moles of methane, we first get its molar mass by adding the masses of C and H. There are C atoms and 4 H atom:
CH4 = 12 + 4*1 = 16 g/mol
Then we divide the given mass by the molar mass:
0.032 mg = 0.000032 g
0.000032 g / (16 g/mol)
= 0.000002 mol or 2 x 10^(-6) mol

To get the molecules present, recall that 1 mole of a substance is equal to 6.022 x 10^23 particles / mol (Avogadro's number). We'll multiply this to the the moles:
6.022 x 10^23 / mol * 2 x 10^(-6) mol
= 1.2044 x 10^18 molecules of CH4

Hope this helps~ :)

Answer 2

Molecule mass of methane ,CH4=12+4=16g mol-1 16 g of methane = 1 mole there for,0.032mg =3.2×10_6 mole methane methane=12.044× 10 raised to17 moles of methane

Answer 3

Molar mass of methane,CH4=12+4=16g mal^-1

16g of methane=1mol
Therefore 0.032mg=10^-5g methane

=3.2*10^-5 mole=2*10^23
mole methane

Now,1mole of methane=6.022*10^23 molecules of methane.

Hence,2*10^-6mole of methane=12.044*10^17 molecules of methane.