Question

Cosmone has the molecular formula C15H26O. Calculate the number of moles of carbon in a 8.35-mol sample of cosmone. Calculate the mass of a sample of cosmone that contains 6.58 x 1019atoms of hydrogen. Calculate the number of atoms of carbon m 8.00-g of cosmone.

Answer 1

Answer:

1) 125.25 moles of carbon

2) 9.35 × 10⁻⁴ grams of cosmone

3) 1.44×10²¹ atoms of carbon

Explanation:

1) The given compound, cosmone, with molecular formula C₁₅H₂₆O has 15 toms f carbon per molecule, therefore, we have

8.35 mole of C₁₅H₂₆O, will contain 15 × 8.35 moles of carbon which is 125.25 moles of carbon

2) The number of moles of hydrogen in 6.58 × 10¹⁹ atoms of hydrogen = 6.58 × 10¹⁹/(6.02 × 10²³) = 1.09 × 10⁻⁴ moles

1 mole of cosmone contains 26 moles of hydrogen, therefore;

1 mole of hydrogen will be contained in 1/26 moles of cosmone

1.09 × 10⁻⁴ moles of hydrogen will be contained in 1/26 × 1.09 × 10⁻⁴moles of cosmone = 4.204 × 10⁻⁶ moles of cosmone

The molar mass of cosmone = 15*12.0107 + 26*1.00784 + 1 * 15.999 = 222.36334 g/mol

Therefore, the mass of 4.204 × 10⁻⁶ moles of cosmone = 4.204 × 10⁻⁶×222.36334  = 9.35 × 10⁻⁴ grams of cosmone

3) The number of moles in 8.00 g of cosmone = 8/222.36 = 0.036 moles

Therefore, number of moles of carbon atoms in 0.036 moles of cosmone = 0.036/15 moles which is 0.0024 moles of carbon;

1 mole of carbon atoms contains 6.02 × 10²³ atoms. therefore;

0.0024 moles of carbon will contain 6.02 × 10²³ × 0.0024 carbon atoms which is 1.44×10²¹ atoms of carbon.