Question

A 10-L drum of ether at 18°C 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 ether at 18°C is 400 torT, what is the pressure inside the dented, sealed drum?

Answer 1

Answer:

final total pressure is 1120 torr

Explanation:

given data

volume v1 = 10 L

volume v2 = 6 L

temperature = 18°C

atmosphere pressure P = 760 torr

volume v3 = 8 L

vapor pressure = 400 torr

to find out

pressure inside the dented

solution

we know here at 6 L volume by small amount of vaporize no temperature will change

and

gas volume in drum is = 10 - 6 = 4L

and

atmosphere pressure = total pressure inside drum

and

partial pressure of air is = 760 - 400

partial pressure of air is  = 360 torr  

so

at 8 L volume sealed and sealed then gas volume inside drum is

gas inside = 760 × $\frac{4}{2}$

gas inside = 1560 torr

so partial pressure either side is

partial pressure = 2× 400  = 800 torr

partial pressure = 2× 360 = 720 torr

so we keep vapor pressure here 400 torr

so

final total pressure = 400 + 720

final total pressure is 1120 torr

Answer 2

Answer:

the final  pressure = 1120 torr

Explanation:

In the starting, when a 10-L drum consist 6 L of ether at 18°C

Volume of gas  $= ( 10 L - 6 L ) = 4 L$

Total pressure of gas which is equal to Atmospheric Pressure = 760 Torr

vapor pressure of liquid (ether) = 400 Torr

vapor pressure of air

$= ( 760 Torr - 400 Torr ) = 360 Torr$

when the drum top is sealed & dented to 8 L capacity

Volume of gas $= ( 8 L - 6 L ) = 2 L$

Total pressure of gasses

$= 760 Torr x ( 4 L / 2 L ) = 1560 Torr$

vapor pressure of ether  $= 400 Torr x 2 = 800 Torr$

vapor pressure of air $= 360 Torr x 2 = 720 Torr$

But some of the liquid (ether) vapor will condensed into liquid just to maintain the vapor pressure of ether at 400 Torr )

therefore, the final  pressure

$= [ 400\ Torr (ether ) + 720\ Torr (air) ] = 1120 Torr$