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May 23, 2015

May 23, 2015

Posted by **Devron** on Monday, August 5, 2013 at 4:36am.

If the pure liquid vapor pressure of benzene is 155 torr and the pure liquid vapor pressure of chloroform is 333 torr, then what is the total vapor pressure at 30°C of a solution of 9.26 g of benzene (C6H6) and 4.26 g of chloroform (CHCl3)?

I get 195torr.

- Dr. Bobb222 -
**DrBob222**, Monday, August 5, 2013 at 11:28amI obtained 196 torr using 78.11 for molar mass C6H6 and 119.377 for molar mass CHCl3.

- Dr. Bobb222 -
**Devron**, Monday, August 5, 2013 at 6:24pmOkay, the answer choices were

The answer choices are:

375 torr

119 torr

195 torr

76.3 torr

When I performed the calculations, I also calculated 196, so i wasn't sure. I don't know if you remember ever taking a multiple choice that required using math as a kid and when you calculated a number, you chose the answer choice closest to the number that matched the number you calculated and getting the answer wrong because of that; I wasn't sure I reverted to a habit that I did as a child, so I wanted a check.

- Dr. Bobb222 -
**Devron**, Monday, August 5, 2013 at 6:55pmOkay, the answer choices are:

375 torr

119 torr

195 torr

76.3 torr

When I performed the calculations, I also calculated 196 torr after rounding up, so I wasn't sure. I don't know if you remember ever taking a multiple choice exam that required using math as a kid and when you calculated a number, you chose the answer choice closest to the number that matched the number you calculated and having the answer marked wrong because of that; I wasn't sure if I reverted to a habit that I did as a child, so I wanted someone to check it.

- Dr. Bobb222 -
**DrBob222**, Monday, August 5, 2013 at 8:40pmI remember taking a multiple guess test in which I picked the closest number to what I calculated but I don't remember it being wrong. I would pick 195 torr also since "none of the above" is not a choice.

- Dr. Bobb222 -
**Devron**, Tuesday, August 6, 2013 at 2:35amYou were more careful then I was as I child. Sometimes I would get careless, or I would just move to fast and not check my work; I do that a lot with my typing. I didn't start applying myself in school until my second year in college. Once I start applying myself, I started to set the curve in some of my courses, or I was at the least one of the sharks and the class. I also began to figure out that I was a nerd.

I didn't want to tell someone something wrong when I was asked about this problem, and if I was wrong, you would tell me.

Thank you