Answer
0.524 M
Work Step by Step
Moles of acetic acid=
$15.0\,mL\, acetic\,acid\times\frac{1.048\,g\,acetic\,acid}{1\,mL\, acetic\,acid}\times\frac{1\,mol\, acetic\,acid}{60.052\,g\, acetic\,acid}$
$=0.261773\,mol$
Molarity= $\frac{\text{Moles solute}}{\text{Litres solution}}=\frac{0.261773\,mol}{500.0\times10^{-3}\,L}$
$=0.524\,M$