The strength of alcoholic beverages like beer, wine, and spirits is typically expressed in units of alcohol by volume or abv. The abv is calculated by dividing the volume of ethanol $($C$2$H$5$OH$)$ by the total volume of solution. If the abv of a strong beer like a doppelbock is $8\mathrm{.}0\%,$ we can express the concentration in other units from the density of H$2$O and C$2$H$5$OH $,$ which are $1\mathrm{.}0$ g$/$mL and $0\mathrm{.}79$ g$/$mL at $20$C $,$ respectively.