Mass- 83g Volume before candle was burnt - 1000 mL Volume after candle was burnt
ID: 878495 • Letter: M
Question
Mass- 83g Volume before candle was burnt - 1000 mL Volume after candle was burnt - 964.2 mLAtmospheric pressure - 1.09 atm Temperature - 296 Kelvins
1) Using the ideal gas law, calculate the number of moles of air originally present in the 250 mL flask 2) calculate the number of moles of air present in the flask after the candles burnt 3) calculate the number of moles of oxygen consumed based on the ideal gas law calculations Mass- 83g Volume before candle was burnt - 1000 mL Volume after candle was burnt - 964.2 mL
Atmospheric pressure - 1.09 atm Temperature - 296 Kelvins
1) Using the ideal gas law, calculate the number of moles of air originally present in the 250 mL flask 2) calculate the number of moles of air present in the flask after the candles burnt 3) calculate the number of moles of oxygen consumed based on the ideal gas law calculations Volume before candle was burnt - 1000 mL Volume after candle was burnt - 964.2 mL
Atmospheric pressure - 1.09 atm Temperature - 296 Kelvins
1) Using the ideal gas law, calculate the number of moles of air originally present in the 250 mL flask 2) calculate the number of moles of air present in the flask after the candles burnt 3) calculate the number of moles of oxygen consumed based on the ideal gas law calculations
Explanation / Answer
1) Volume before candle was burnt - 1000 mL
but in 250 ml flask only 250 ml air can occupied
so volume = 250 ml = 0.25 L
P V = n RT
1.09 x 0.25 = n x 0.0821 x 296
n = 0.0112
before burnt moles of O2 present = 0.0112 moles
2)
1000 (before voluem )---------------------> 964.2 (remaining after burn)
250 (flask ) ---------------------> ? (remaining in the flask)
remaining volume in 250 ml falsk after burnt = 964.2 x 250 / 1000
= 241.05 ml
= 0.241L
PV = n RT
1.09 x 0.241 = n x 0.0821 x 296
n = 0.0108
after burnt moles of O2 present = 0.0108 moles
3) volume of oxygen consumed = 250-241.05
= 8.95 ml
= 0.00895L
PV = nRT
1.09 x 0.00895 = n x 0.0821 x 296
n = 4 x 10^-4
4 x 10^-4 moles oxygen consumed .