Multiple choice

The vapour pressure of pure water is $32.8 mm$ of $Hg$. It is mixed with ethanol which has mole fraction $0.9$. Find the vapour pressure of the resulting solution:

  1. $39.3 mm$ $Hg$
  2. $36.0 mm $$Hg$
  3. $29.5 mm$ $Hg$
  4. $28.8 mm$ $Hg$
Reveal answer Fill a bubble to check yourself
C Correct answer
AI explanation

The question does not specify the vapour pressure of ethanol, making an exact calculation of the final pressure using Raoult's Law impossible from the provided text alone. However, if we strictly follow the most direct interpretation of Raoult's Law and assume the given mole fraction of 0.9 applies to water in the mixture, the partial pressure of water is 0.9 multiplied by 32.8, yielding 29.52. The final vapour pressure of the resulting solution is 29.5 mm Hg.

Keep practicing — related questions