Monday

September 22, 2014

September 22, 2014

Posted by **Alexandria** on Sunday, December 31, 2006 at 10:20pm.

A two-liter soft drink bottle can withstand a pressure of 5 atm. Half a cup [approximately 120 mL) of ethyl alcohol C2H5OH, (d= 0.789 g/mL) is poured into a soft drink bottle at room temperature. The bottle is then heated to 100 degrees C [3 sig figs], changing the liquid alcohol to a gas. Will the soft drink bottle withstand the pressure, or will it explode?

My work:

P= nRT/V

to find n:

.789 g/mL x 120 mL = 94.68 g = xmol x 46.08 g/mol

x= 2.055 mol

(2.055 mol x .08206 L x atm/mol x K x 373.15 K) / 2 L

= 31.46 atm

This number seems high to me. Am I setting up the problem correctly?

You have done it correctly, if the assumption that all of the ethyl alcohol vaporizes is valid. The way they worded the question, you cannot say for sure if they expect you to assume that it all evaporates. If it does, it is ok to use the ideal gas law, as you have done.

However, you need to consider the vapor pressure of alcohol as a function of temperature to see if it can all evaporate. Extrapolating from vapor pressure data I can find, and using a log P = a + b/T fit, it is appears that the vapor pressure of C2H5OH is about 2 atm at 100 C. (It is 1 atm at 78.5 C.) This means that the vapor pressure in the bottle will rise to a temperature insufficient to break the bottle, and that most of the alcohol will remain in liquid form.

- Chemistry -
**Rachael**, Sunday, October 17, 2010 at 6:13pmYou may have copied the question wrong because I had the same one for homework, only d=0.789g/L instead of g/mL. That error would account for your unusually high number

**Answer this Question**

**Related Questions**

Algebra - I am having trouble with the following problem can someone please help...

Excel Graphs - i'm having trouble getting my graph to come out right in the ...

algebra - I'm having trouble getting the symbols to post correctly on this page ...

Calculus - I'm having trouble trying to figure this problem out, I know the ...

math - posting again. my daughter is having trouble in input output finding the ...

Math - Can someone explain this problem to me, I cannot figure out how they came...

Math - I need someone to show me how to work these two problems out. 30. find ...

Chemistry - Trying to figure out this equation I did the first part but I am ...

Chemistry - Trying to figure out this equation I did the first part but I am ...

chemistry - Trying to figure out this equation I did the first part but I am ...