Suppose someone had an excessive Friday evening drinking party and then did the ultra-dumb thing of driving home while drunk. Luckily, the person got pulled over by the police before they can injure anyone else. The police took a blood alcohol reading of 1.80 % (expressed as a mass-based ratio), which is an extreme DUI offense. What was the concentration of alcohol in the blood expressed as molarity? (assume blood has the same density as water and the alcohol is ethanol, C2H6O). The error interval is 5%.
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1.80% means 1.8 g/100 g solution. If the density of the solution is 1.0 g/mL, then that is 1.8 g/100 mL or 18g/1000 mL = 18 g/L.
Convert 18 g to mols to convert to mols/L = M.