Anonymous
Anonymous asked in Science & MathematicsChemistry · 9 years ago

what is the percent by mass of carbon in octane, C8H18?

the 8 and 18 are subscripts

2 Answers

Relevance
  • Norrie
    Lv 7
    9 years ago
    Favorite Answer

    Octane C8H18 Mol.mass = (C:12 x 8) + (H:1 x 18) = 96 + 18 = 114g/mol.

    Of this: C: = (96 / 114) x 100% = 84.21% Carbon.

    (Check for hydrogen being 15.79%: H: = (18/114) x 100% = 15.79%

    Total = 100%...check.

  • ?
    Lv 4
    4 years ago

    Octane C8h18

Still have questions? Get your answers by asking now.