Elements: Mercury (HD)

How heavy is a jar of Mercury? Why is it so important to chemists? Dr Andrea Sella demonstrates.

Created to support the Elements event at Wellcome Collection on 8 April 2011, for more information see http://www.wellcomecollection.org/elements

Category:

Science & Technology

Tags:

• mercury
• quicksilver
• chemistry
• andrea sella
• ucl
• wellcome collection
• manometer
• pressure measurement
• educational

[superhuman641]

How does mercury measure the pressure of a gas?

[WellcomeCollection]

@superhuman641 Hi Superhuman641, looks like we've had a great response to your question. See above.

[ChemModule5]

The mercury is contained in a U-tube. If the pressure on both sides of the tube is the same, the levels of the liquid will be the same. But if you change the pressure on one side or the other the mercury will rise up in response to the difference until the pressure due to the weight of mercury exactly balances the additional applied pressure. And the height is directly proportional to the pressure. So it's very simple and very visual; a real window into the invisible world of gases and vacuum.

[Transparent914]

great video!