Friday, February 15, 2008
ChemistryChapter 2.5Collecting Gases and Measuring Volume of Gasesdisplacement of water is suitable for
collecting gasesthat are soluble in water. Carbon dioxide, hydrogen, or oxygen
can be collected by this method.
downward delivery should be used to
collect gasesthat are soluble in water and denser than air,
such as chlorine and hydrogen chloride.
upward delivery should be used to
collect gasesthat are soluble in water and less dense that air,
such as ammonia.
How to collect a dry sample of gas?drying agent, conc sulphric acid, quicklime (calcium oxide)
and fused calcium chloride.
Conc. sulphuric acid is used to dry most gases
including chlorine and hydrogen chloride.
However, it can not be used to dry ammonia
because it reacts with ammonia.
things to take note of:
tube introducing the gas is
immersed in the acid while the exiting tube is not.
Chapter 9 The Mole1 mole = 6.02 * 10^23
Mole = Mass / relative atomic mass or relative molecular mass
Molar Mass = Mole * relative atomic mass or relative molecular mass
Molar Vol. (gas) = 24dm³
http://www.moe.gov.sg/edsoftware/ir/files/chem-mole/index.htmlLabels: collecting gases, displcement of water, downward delivery, dry agent, molar mass, molar volume, mole, upward delivery
for now and ever...
8:40 PM