Verified Answer :


a sample has 3.28 X 10^24 h atoms
  so first we will find the moles of Hydrogen by putting values in formula 
that is
. moles = no. of atoms/ Avogadro's no (NA)
moles
 = 5.446 we got this
 now the ratio of Carbon and Hydrogen is:
C = H

      3 = 8

now multiply it with the moles
      3/8 5.466 = 5.466
2.05 is the moles of C
.
now:find the no of C atoms by this
 = moles X NA

 = 2.05 X 6.022 X 10^23
 = 1.27 X10^2
now will find the mass of sampl:
  so One mole of C3H8 = 3 moles of C
1/3 2.05 = 2.05 moles of C
 0.68 moles of C3H8.

 now the mass of C3H8 = moles X molar mass
mass of C3H8
 which is = 0.68 X 44 =
 30.2 grams of C3H8
hope it helps

Dejanras

1) N(H) = 3.28·10²⁴; number of hydrogen atoms.

n(H) = N(H) ÷ Na(Avogadro constant).

n(H) = 3.28·10²⁴ ÷ 6.022·10²³ 1/mol.

n(H) = 5.44 mol.

According to molecular formula of butane: n(H) : n(C) = 8 : 3.

n(C) = (5.44 mol · 3) ÷ 8.

n(C) = 2.04 mol; amount of substance.

N(C) = 2.04 mol · 6.022·10²² 1/mol.

N(C) = 1.23·10²⁴, number of carbon atoms.

2) n(C₃H₈) : n(C) = 1 : 3.

n(C₃H₈) = 2.04 mol ÷ 3.

n(C₃H₈) = 0,68 mol.

m(C₃H₈) = n(C₃H₈) · M(C₃H₈).

m(C₃H₈) = 0.68 mol · 44.1 g/mol.

m(C₃H₈) =29.99 g; mass of the sample.