How many carbon atoms are in 4.00g of butane

1.6221*10^23 atoms

Explanation:

Butane = C4H10

Molar mass = 58g/mol

1 mole of butane has 4 carbon atoms.

% of carbon in 1 mole of C4H10 = 4*12/58 =82.8%

Mass of carbon in 4g of butane = 82.8/100 *4 = 3.312g.

3.312g of carbon is equal to how many moles of carbon?

No.of moles = mass/ molar mass

3.312/12 = 0.276 moles.

Using Avogadro's number,

Number of atoms in any substance = Avogadro's constant * no of moles of that substance

(6.02214*10^23) * 0.276 = 1.6221*10^23 atoms.