#### Answer

a) $13600\,kg/m^{3}$
b) $3.40\,kg$

#### Work Step by Step

a) $13.6\,g/cm^{3}=\frac{13.6\,g}{cm^{3}}\times\frac{kilo}{1000}\times\frac{cm^{3}}{10^{-6}m^{3}}=13600\,kg/m^{3}$
b) Mass= Density$\times$Volume= $13600\,kg/m^{3}\times0.250\,L\times\frac{1m^{3}}{10^{3}L}=3.40\,kg$