Finding a mass

Question

The concentration of carbon monoxide in an urban apartment is 48 μg/m^3. What mass of carbon monoxide in grams is present in a room measuring 11.5 x 11.5 x 20.5 ft?

Answer 1

The first thing you need to do is convert the dimensions to meters.

 

ex) 11.5ft*(12in/1ft)*(2.54cm/1in)*(1m/100cm) =3.51m           I show the unit conversions here as well

 

you should get 3.51, 3.51, and 6.25m for the dimensions which you then multiply together

 

the volume of the room is 76.98m^3

 

now you need to convert 48ug/m^3 so that it is g/m^3

 

to do that, divide 48 by 1x10^6                   * 1x10^6 ug=1g *

 

you should get 4.8x10^-5 g/m^3

 

that value is then multiplied by the volume of the room to cancel out the m^3 units leaving the amount of grams of carbon monoxide in the room

 

CO in the room = 3.70x10^-3g