Answer: a.
of carbon
b.
of hydrogen
c.
of oxygen
Step-by-step explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the moles, we use the equation:

a) 1 mole of ethanol
contains =
of carbon
Thus 0.989 moles ethanol
contains =
of carbon
b) 1 mole of ethanol
contains =
of hydrogen
Thus 0.989 moles ethanol
contains =
of hydrogen
c) 1 mole of ethanol
contains =
of oxygen
Thus 0.989 moles ethanol
contains =
of oxygen