Answer
$4.67\%$ $C_{6}H_{5}OH$
Work Step by Step
Formula:
mass percent = $\frac{mass solute}{mass solution}$ x 100
Given:
mass of solute (phenol) = 20.8 g $C_{6}H_{5}OH$
mass of solvent (ethanol) = 425 g $CH_{3}CH_{2}OH$
mass of solution = mass of solute + mass of solvent
Substitution of values:
mass of solution = 20.8 g $C_{6}H_{5}OH$ + 425 g $CH_{3}CH_{2}OH$ = 445.8 g
mass percent = $\frac{20.8 g C_{6}H_{5}OH }{445.8 g solution}$ x 100
mass percent $= 4.6657 \approx 4.67\% C_{6}H_{5}OH$
