mass (m) = ? , volume = 18.0 ml , density = 1.42 g/ml .
[tex]density = \frac{mass}{volume} \\ \\ d = \frac{m}{v} \\ \\ mass = density \times volume \\ \\ m = d \times v \\ \\ m = 18 \: ml \times \: 1.42 \: \frac{g}{ml} \\ \\ m = 25.56 \: g[/tex]
I hope I helped you^_^
