(26 Sep 2013)
Electrolysis of Water
(in class guidance)
Can water be broken down into its component parts. Does it have component parts?
Set up experiment
1. Fill tank: Pour a premeasured sodium hydroxide solution from a bottle into the clear plastic
containing two stainless steel screws (pointing into the box). The liquid should cover the
screws and then some.
2. Place + test tube in box: Wearing gloves, put a capped test tube labeled + into the liquid in
the box, cap down. Open the cap underwater (turn the tube counterclockwise), without letting
any air in. Then slide the tube over the screw on the side of the box labeled +.
3. Place ̶ test tube in box: Wearing gloves, put a capped test tube labeled ̶ into the liquid in
the box, cap down. Open the cap underwater, without letting any air in. Then slide the tube
over the screw on the side of the box labeled ̶
4. Put lid on apparatus: Slide the plastic lid with two holes
over the two tubes, making sure that the red plus side
matches the red plus side of the box.
5. Transfer apparatus to battery: Lift the apparatus (box
plus tubes plus lid) and place it on a cream cheese
container with a 9V battery sitting in it. Make sure the
plus tube is sitting over the plus side of the battery and
the minus tube is sitting over the minus side of the
battery.
6. Note time of start: Write down the time to the nearest
minute that the apparatus made contact with the battery.
Apparatus after Step 5.
7. Check status: After about 5 minutes, check the tubes to see if any gas is accumulating.
8. Remove apparatus from battery: About 45 minutes after the start of the experiment (noted in
#6), lift the apparatus off the cream cheese container and rest it on a yogurt container.
9. Note time of stop: Write down the time to the nearest minute that the apparatus broke contact
with the battery.
10. Cap (+) test tube: Wearing gloves, slide the plus tube over the screw and put a cap on it
(turning the tube clockwise), all underwater, not allowing any air to enter the tube. Then take
the tube out of the apparatus and let it rest in the test tube rack (an inverted egg carton).
11. Cap (̶ ̶) test tube: Wearing gloves, slide the minus tube over the screw and put a cap on it
(turning the tube clockwise), all underwater, not allowing any air to enter the tube. Then take
the tube out of the apparatus and let it rest in the test tube rack (an inverted egg carton).
(26 Sep 2013)
12. Note volume of gas in (+) test tube: Measure the amount of gas in the plus test tube while the
tube is inverted (cap-side down) by reading the number next to the air-water interface. Write
down this number.
13. Note volume of gas in (̶ ̶) test tube: Measure the amount of gas in the minus test tube while
the tube is inverted (cap-side down) by reading the number next to the air-water interface.
Write down this number.
Group A
Steps 1 and 12
Steps 2 and 13
Steps 3 and 9
Steps 4 and 7 and 8
Steps 5 and 10
Steps 6 and 11
Kevon
Jonathan O.
Ziyuan
Shania
Luis
Keven
Group B
Steps 1 and 7 and 12
Steps 2 and 13
Steps 3 and 8
Steps 4 and 9 and 10
Steps 5 and 6 and 11
Kareema
Melisa
Jorge
Amarion
Cianai
Group C
Steps 1 and 7 and 12
Steps 2 and 13
Steps 3 and 8
Steps 4 and 9 and 10
Steps 5 and 6 and 11
Layla
Terra
Kamari
Jonathan S.
Breonna
Group D
Steps 1 and 12
Steps 2 and 13
Steps 3 and 9
Steps 4 and 7 and 8
Steps 5 and 10
Steps 6 and 11
Ta'jonte
Robert
Demarco
Michael
Griselda
Tori
1. Fill tank
2. Submerge (+) test tube
3. Submerge (-) test tube
4. Put lid on apparatus
5. Transfer apparatus to battery
6. Note time of start
7. Check status
8. Remove apparatus from battery
9. Note time of stop
10. Cap (+) test tube
11. Cap (-) test tube
12. Note volume of gas (+)
13. Note volume of gas (-)
-----------------Notes
Step 1: Solution is 470 ml of 0.1 M NaOH (5.6 g/liter) in a clear tofu container. Sodium bicarbonate also works, but
complicates matters by producing carbon dioxide.
Step 2 and 3: Graduated 15 ml plastic centrifuge tubes were used. The stainless steel (not galvanized!) screws can be
replaced by a common pencil, sharpened at both ends.
Step 14: Try applying to one side a toothpick that has been set on fire and to the other a toothpick that has been set
on fire and then blown out.