Question
ID: 975333 • Letter: Q
Question
A 10-L drum of ether at 18C is open to the atmosphere (p=760 Torr) and contains 6-L of liquid. The top is sealed and the drum dented so that it now has an 8-L capacity.If the vapor pressure of the ether at 18C is 400 Torr, What is the pressure inside the dented sealed drum? Question A 10-L drum of ether at 18C is open to the atmosphere (p=760 Torr) and contains 6-L of liquid. The top is sealed and the drum dented so that it now has an 8-L capacity.If the vapor pressure of the ether at 18C is 400 Torr, What is the pressure inside the dented sealed drum? Question A 10-L drum of ether at 18C is open to the atmosphere (p=760 Torr) and contains 6-L of liquid. The top is sealed and the drum dented so that it now has an 8-L capacity.If the vapor pressure of the ether at 18C is 400 Torr, What is the pressure inside the dented sealed drum? A 10-L drum of ether at 18C is open to the atmosphere (p=760 Torr) and contains 6-L of liquid. The top is sealed and the drum dented so that it now has an 8-L capacity.If the vapor pressure of the ether at 18C is 400 Torr, What is the pressure inside the dented sealed drum?Explanation / Answer
Volume of liquid ether remains at 6 L , No Temperature change when small amount of ether vaporize or condense.
At the beginning , when a 10-L drum containing 6 L of ether at 18oC is open to the atmosphere ( P = 760 Torr )
Volume of gas inside the drum = ( 10 L - 6 L ) = 4 L
Total pressure of gas inside the drum = Atmospheric Pressure = 760 Torr
Partial pressure of ether = 400 Torr
Partial pressure of air = ( 760 Torr - 400 Torr ) = 360 Torr
Immediately , when the drum is sealed and dented to 8 L Volume
Volume of gas inside the drum = ( 8 L - 6 L ) = 2 L
Total pressure of gasses inside the drum = 760 Torr x ( 4 L / 2 L ) = 1560 Torr
Partial pressure of ether should be = 400 Torr x 2 = 800 Torr
Partial pressure of air should be = 360 Torr x 2 = 720 Torr
But some of the ether vapor will condensed into liquid ( to keep vapor pressure of ether at 400 Torr )
Then the final total pressure should be [ 400 Torr ( from ether ) + 720 Torr ( from air ) ] = 1120 Torr