V
From reaction
mercury
lock
pump
air
mercury
This is the situation at the start of your experiment. The
entire system is at vacuum, and the mercury is at the
bottom part of the Toepler pump.
V
pump
The valve at the right-hand side is directed to the pump
to retain the mercury at the bottom part.
V
pump
After opening the reaction vessel, the gas formed in the
reaction will enter the top part of the Toepler pump.
V
air
By directing the valve to atmospheric pressure, the
mercury will be pushed upwards, thus compressing the
gas that was in the upper part.
V
air
At a certain point, the compressed gas will be pushed
through the mercury lock.
V
pump
By directing the valve back to the pump again, the
mercury will be transferred back to the bottom .
V
pump
When the mercury is transferred back to the bottom
part, the remaining gas will equilibrate.
V
air
Now the cycle will be repeated.
Compressing the gas
V
air
Now the cycle will be repeated.
Pushing the gas through the mercury lock
V
pump
Now the cycle will be repeated.
Transferring the mercury back to the bottom part.
V
pump
Now the cycle will be repeated.
Allowing the gas to equilibrate
V
pump
At a certain point, all the gas is transferred into the
calibrated volume. Now you can push the mercury
upwards...
V
mark
air
…until the mark which indicates the limit of the
calibrated volume is reached.
V
Dp
air
You can measure the pressure in the calibrated
volume, by reading the difference in height in the two
legs, and calculate the amount of gas.