Map Sapling Learning macmilan learning The Occupational Safety and Health Admini

Question

Map Sapling Learning macmilan learning The Occupational Safety and Health Administration has set the limit on the maximum percentage of carbon dioxide (CO2) in air a worker can breathe at 0.500% by mole. if dry ice (solid CO2) is sublimating (becoming a gas) in a room at a rate of 0.150 mol/min, what is the minimum rate that fresh air has to be supplied to the room so that the concentration of CO2 in the room doesn't exceed 0.500% by mole? Assume the room is well mixed, and the volume of the solid dry ice does not change. Number 183.08 mol air min What is the percent by mass of oxygen in a gaseous mixture whose molar composition is 0.500% CO2 and g/mol 99.500% air? The composition of air is 21% mole 02,79% mole N2, and has an average molar mass of 29.0 Number 23.124 %02 by mass Incorrect Previous 8 Give Up & View Solution Try Again O Next H Exit Explanation

Explanation / Answer

Now here we have molar flow rate of carbon dioxide =0.15 mol/min

Now the maximum allowable mole fraction of carbon dioxide in the stream is 50 %

Hence the total molar flow rate of stream will be = 0.15/0.5 = 30 mol/min

Hence, Molar flow rate of fresh air = 0.3- 0.15 = 0.15 mol/min

To find the weight percent of Oxygen we will assume some basis

Let total moles = 1 mol

mols of CO2 = 0.005

molar mass of Carbon dioxide = 44 g/mol

Weight of CO2 = 0.005*44 =0.22 grams

mols of air = 0.995

molar mass of air =29 g/mol

weight of air = 29*0.995 =28.855 grams

Total weigt of sample = 0.22+28.855 = 29.075 grams

now composition of air is 21 % oxygen and 79 % nitrogen

Oxygen mols = 0.21*0.995 =0.20895 mols

molar mass of oxygen = 32 g/mol

weight of oxygen =0.20895*32 =6.6864 grams

Nitrogen mols = 0.995 - 0.20895 =0.78605 mols

Weight fraction of oxygen = (Weight of oxygen)/ (Total weight of sample) = 6.6864/29.075 =0.229

which is approximately 23 % oxygen

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---