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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: lylyan_aki on May 16, 2018, 11:50:23 PM

Title: Toluene concentration in ppm
Post by: lylyan_aki on May 16, 2018, 11:50:23 PM
Hi, I need help with this question.

A worker drops a one gallon bottle of toluene that is 20% full on the floor of a work room that is 30x50x10 feet. The general ventilation fan is broken the door is closed and there is no window. Assuming perfect mixing what is the final concentration of toluene in the air in ppm when it has all evaporated. (note remember you have a formula for lb molecular weight of 379 cf/lb-mole and the density of toluene is 0.865 with a molecular weight of 92.1).

What is the concentration in ppm of toluene?

Title: Re: Toluene concentration in ppm
Post by: Borek on May 17, 2018, 04:37:27 AM
You have to show your attempts to receive help, this is a forum policy.

Why don't you start by listing related definitions and formulas? Is there anything you can calculate from the data given?
Title: Re: Toluene concentration in ppm
Post by: lylyan_aki on May 17, 2018, 11:00:30 PM
What I'm having right now is

- Converted 0.2 gal to 757.082 ml
- Looked for mass of toluene spilled: 0.865 g/ml x 757.082 ml = 654.876 g

- Volume of the room: 30x50x10 = 15,000 cubic ft
- Converted to cubic meter: 15000 cubic ft = 424.7527 cubic meter
- Concentration of toluene in the room: 654.876 g / 424.7527 cubic m = 1.54178 g/m3 = 1541.8 mg/m3
- Convert to ppm: 1541.8 mg/m3 with molecular weight of 92.1 = 409.31 ppm
Title: Re: Toluene concentration in ppm
Post by: jestearns on May 18, 2018, 01:20:39 AM
Can you kindly show your work and units in the last step?
Title: Re: Toluene concentration in ppm
Post by: sjb on May 18, 2018, 03:58:23 AM
Can you kindly show your work and units in the last step?

...and possibly the first step too?
Title: Re: Toluene concentration in ppm
Post by: DrCMS on May 18, 2018, 04:31:22 PM
Can you kindly show your work and units in the last step?

...and possibly the first step too?

No, for tiny freedom gallons it is correct but for proper Imperial gallons it is not.