解：$(1)$水的密度$ρ_{水}=1.0×10^3\ \mathrm {kg/m}^3=1.0\ \mathrm {g/cm}^3，$瓶子装满水后，水的质量$m_{水}=m_{总1}−m_{瓶}=550\ \mathrm {g}−50\ \mathrm {g}=500\ \mathrm {g}，$由$ρ=\frac {m}{V}$可得水的体积，即瓶子的容积$V=V_{水}=\frac {m_{水}}{ρ_{水}}=\frac {500\ \mathrm {g}}{1.0\ \mathrm {g/cm}^3} =500\ \mathrm {cm}^3$
$(2)$酱油的密度$ρ_{酱油}=1.1×10^3\ \mathrm {kg/m}^3=1.1\ \mathrm {g/cm}^3，$瓶子装满酱油时，酱油的体积$V_{酱油}=V=500\ \mathrm {cm}^3，$酱油的质量$m_{酱油}=ρ_{酱油}V_{酱油}=1.1\ \mathrm {g/cm}^3×500\ \mathrm {cm}^3=550\ \mathrm {g}$
$(3)$酒的质量$m_{酒}=m_{总2}−m_{瓶}=500\ \mathrm {g}-50\ \mathrm {g}=450\ \mathrm {g}，$酒的体积$V_{酒}=V=500\ \mathrm {cm}^3，$酒的密度$ρ_{酒}=\frac {m_{酒}}{V_{酒}}=\frac {450\ \mathrm {g}}{500\ \mathrm {cm}^3}=0.9\ \mathrm {g/cm}^3=0.9×10^3\ \mathrm {kg/m}^3$
