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Topic: ppmv?  (Read 6694 times)

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Offline qazse

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ppmv?
« on: February 17, 2012, 06:24:55 AM »
"The running engine of an automobile produces carbon monoxide (CO), a toxic gas, at the rate of about 188 g CO per hour. A car is left idling in a poorly ventilated garage that is 5.3 m long, 4.0 m wide, and 2.2 m high at 20°C.

How long would it take to build up a lethal concentration of CO of 1000 ppmv (parts per million by volume)?"

thankyou

Offline sjb

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Re: ppmv?
« Reply #1 on: February 17, 2012, 06:32:43 AM »
"The running engine of an automobile produces carbon monoxide (CO), a toxic gas, at the rate of about 188 g CO per hour. A car is left idling in a poorly ventilated garage that is 5.3 m long, 4.0 m wide, and 2.2 m high at 20°C.

How long would it take to build up a lethal concentration of CO of 1000 ppmv (parts per million by volume)?"

thankyou

What is the volume of that amount of carbon monoxide (assume atmospheric pressure)? Of the garage?

Offline qazse

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Re: ppmv?
« Reply #2 on: February 17, 2012, 06:36:34 AM »
How to convert the ppmv to the volume?

Offline Hunter2

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Re: ppmv?
« Reply #3 on: February 17, 2012, 06:44:39 AM »
There is no conversion. ppmv is similar like %. It is a ratio number.

If you would have 1 million liter then 1 liter is 1 ppmv

Offline Grant N.

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Re: ppmv?
« Reply #4 on: February 17, 2012, 07:09:46 PM »
ppmv is a unit of concentration.

(1) ppmv= [(species moles)/(total moles)] x 10^6.

For instance if you wanted to know how many moles of CO are in 1 cubic meter of air with a concentration of 10 ppmv CO, you use the ideal gas law and use the temperature you have.

(2) PV=nRT

1 cubic meter = 1000L
n= moles of air*
*AIR NOT CO*
R= 0.0821 (L*atm/mol*K)
T= 273K + degrees celsius
P= 1atm (unless otherwise specified)

(1 atm)(1000L)= (n air)(0.0821 L*atm/mol*K)(293K) at 20 degrees celsius

Once you get moles air, you plug in that and the 10 ppmv of CO on the other side of equation (1) to get the mol of CO in that amount of Air. I'm sure you can figure out the rest from there using the dimensions you have.

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