7/25/2019 1.01 Experiment 1 Diffusion in Gases
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Experiment 1. Diffusion in gases
You are provided with two glass tubes equal in length and
diameter and marked at 2 cmintervals.
(a)Copy the table given below into your notebook and collect a
little cold water in abeaker or other container .
(b)Using forceps, pick up a square of red litmus paper, dip it
in the water, shake offsurplus water and place the paper inside one
of the glass tubes. Use the wire or glassrod to manipulate the
litmus paper until it is stuck to the glass immediately under the1
cm mark !see "ig. 2, p.1.2#. $epeat this operation for the
remaining marks in bothtubes, working from the end of the tube
nearer the marks.
(c)Close the 2% cm end of both tubes with the ordinary cork
bungs.&he ne't operation involves ammonia solutions, one of
which is very strong and gives offa pungent vapour. (t is harmless
enough provided you do not deliberately sniff it at closerange.
(d)&ake the corks with cotton wool plugs to the central
dispensing point in the laboratoryand use the dropping pipette to
place about 2 drops of strong !)*# ammonia solutionon the cotton
wool in cork + and an equal number of drops of dilute !2*#
ammoniasolution on the cotton wool in cork .
(e)*ote the time and insert each cork in the appropriate tube at
the same time.
(f)(n your table, note the time interval required for each
square of litmus to turncompletely blue and continue recording
until the litmus at 2% cm in one of the tubes hasturned blue.
(g) -ake a graph of distance against time, plotting the values
for both tubes on the samegraph, with time on the horiontal
scale.
&imestarted
...........
/istance along tube in cm 1 12 10 1 1% 2 22 20 2 2%
Atrong ammonia solution*umber of minutes from start
B3eak ammonia solution*umber of minutes from start
/iffusion 1.1
