Answer
$7.0 \times 10^{22}C_2H_5OH$ molecules
Work Step by Step
We know that one $C_2H_5OH$ molecule has 6 hydrogen atoms
So $4.2\times 10^{23}H\space atoms\times\frac{1 C_2H_5OHmolecule}{6H atoms}=7.0 \times 10^{22}C_2H_5OH$ molecules
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