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P-6
There are several types of ammeters used for this experiment. Your laboratory instructor will tell you which
setting to use on your meter.
Obtain a long copper wire and an insulated wire with a nichrome tip and begin to assemble the apparatus
shown in Figure 1 following the procedure given in the next 3 paragraphs. Your laboratory instructor will
explain the assembly of this apparatus and there will also be a demonstration model set up for you to look at.
NOTE: All of the exposed nichrome wire must be inside the buret, including a short segment of
the insulated portion, however, DO NOT push the tip too far up the buret or else you will
not be able to get a sufficiently strong current.
Wash the copper wire with distilled water to ensure that the surface is clean and dry it thoroughly. This will be
the copper anode. Accurately weigh your copper wire to
0.001 g. Coil the end of the wire that will be
submerged in the acid.
Pour 250 mL of distilled water into a 400 mL beaker. Using the automatic dispenser, carefully add 20 mL of
6.0 M H2SO
4
to the beaker and stir to produce a 0.45 M H2SO
4
solution. Insert the nichrome wire into the
open end of the buret and set up both as illustrated in Figure 2. Have the buret resting on the bottom of the
beaker to ensure that the nichrome wire will not be moved from its position in the buret.
Open the stopcock on the buret and use a squeeze bulb to draw up the H2SO
4
solution into the buret. Close
the stopcock when the solution is at about the 30 - 35 mL level in the buret. Make sure that the copper wire
is well immersed in the H2SO
4
solution.
Connect the insulated nichrome electrode (cathode) to the negative terminal (black) of your voltage source.
Put the coiled end of the copper wire into the H2SO
4
solution and connect the other end of the copper wire to
the yellow outlet on the resistance box.
Connect the multimeter to form the circuit. Be sure all the settings and connections on the multimeter are
correct and all connections are tight:
