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.
