What is OxiClean used for?

Institute Dr. Flad
Vocational college for chemistry, pharmacy, biotechnology and the environment

Experiments with "Oxi cleaners"

Simple experiments using "Oxi-cleaners" as an oxygen source: from oxygen detection through "burning" foam to "sparklers" made from sponge wire and a blast furnace model in a test tube to the quantitative determination of the oxygen content of the released gaseous substances.

The following test instructions from Marco Rossow and Prof. Dr. Alfred Flint, University of Rostock, come from the lecture "Chemistry for Life - Oxygen from Oxygen Cleaners" and from the workshop "Substances from everyday life in chemistry lessons - Experiments with Oxygen cleaners", presented at the Dr. Flad as part of the 12th Stuttgart Chemietage.

 

Test instructions: experiments with "Oxi cleaners"

 

Since the manufacturers of Oxi cleaners (unfortunately for us) occasionally change the composition of their products, it is imperative to test the desired / purchased cleaner before using it in the classroom!

For example, the successor product to the "Vanish Oxi action®" we use, the "Vanish Oxi action max®", contains significantly more surfactants. These can be decomposed when heated. On the one hand, this leads to a significant amount of smoke. On the other hand, flammable cracking products can arise, which can then lead to deflagrations in the glow chip test or in quantitative analyzes in connection with the oxygen that is also released.

According to the current status, some remedy can be found in the following way:
First of all, the grain size of the cleaner to be used must be checked. Products that contain components with different grain sizes are suitable. Such a cleaner can be put in a "Fackelmann" tea strainer (has exactly the right pore size) and sieved out. The mostly fine-grained to powdery surfactants fall through the sieve, the somewhat coarser components containing the sodium carbonate peroxohydrate remain in the sieve and can then be used for the experiments.

If there are several cleaners, a clear difference in the grain size of the individual components can be observed (Domol "oxi Aktivkraft", AS "Oxy", Heitmann "OXI"). The coarse-grained constituents are usually sodium carbonate peroxohydrate, while the more fine-grained constituents are the added surfactants, enzymes, etc. If, as in our experiments, you need the bleaching agent, if possible without any further additives, it will pass Separate seven. However, the correct pore size of the sieve is important! In our experience, the tea strainers from Fackelmann® are particularly suitable, with which you can easily separate the components not desired for the experiment by shaking several times. The bleaching agent that can be used for the experiment then remains in the sieve, largely without any other interfering additives. The environmentally and of course price-conscious experimenter will of course collect the other constituents when sieving and feed them for further recycling, after all you can at least remove grease stains with them.

Following a tip from a colleague, we discovered that Individual detergent components are sold in many organic shops. This also includes an oxygen-based bleaching agent (e.g. Ecover®), which does not contain any surfactants, enzymes or other similar components and is very suitable for the experiments. 400 g of this bleach cost between € 2.49 and € 2.89.

 

 

Equipment / chemicals:150 mL beaker, hot plate, thermometer, "Hoffmanns Vanish Oxi action", linen cloth, red wine
Execution:First, create a clear red wine stain on the linen cloth. Then fill the beaker about halfway with water, add a measuring spoon of "Hoffmanns Vanish Oxi action®", dip the linen cloth into the solution and place a thermometer in it. The solution is gradually warmed on a hot plate. If this is not available, the beaker can also be clamped in and the solution carefully and slowly heated with a burner.
Observations:When heated, the red wine stain gradually turns brown and then discolored. At the same time, starting from around 35 ° C, gas evolution begins to increase with increasing temperature, and a foam layer forms on the solution.
Evaluation:Obviously, the cleaning agent "bleaches" the red wine stain, and the gas produced seems to play a role in this.

 

Experiment 2: Detection of released oxygen (brief description)

Approx. 75 mL tap water is poured into a 150 mL beaker and heated to 60 ° C. Then add approx. 15 g Oxi-Cleaner and a small drop of diluted washing-up liquid (washing-up liquid and water in a ratio of 1: 3). You wait until a 3 cm high head of foam has formed and then pierce individual bubbles with a glowing wood chip or "stir" the foam. Especially when "stirring" the glowing chip lights up brightly and starts to burn. The foam should consist of larger bubbles, as a too moist, fine-pored foam prevents the chip from igniting.

 

Experiment 3: Heating of "Hoffmanns Vanish Oxi action®" (brief description)

You put about one gram of the cleaner in a test tube, heat it with a burner and after a short time hold a glowing wood chip in it, which then spontaneously flares up. When using a semi-micro test tube, heating with a candle is sufficient.

 

Experiment 4: Combustion of charcoal with and without supply of oxygen (brief description)

About three centimeters high "Hoffmanns Vanish Oxi action®" are placed in a diagonally clamped test tube, a loose wad of glass wool and a piece of charcoal on top of it at a distance of about six centimeters. First, only the charcoal is heated vigorously with a burner, then you swivel the flame on the cleaner.

The charcoal begins to glow slightly, but no reaction worth mentioning can be observed. If you then heat the cleaner, the charcoal lights up brightly and burns with a glowing flame.

 

In a Duran test tube (18 x 180 mm) you put an Oxi-Cleaner about 5 - 6 cm high, over it about 2 cm high small pottery shards, then cover about 5 cm high with previously annealed granulated activated carbon (grain 2.5 mm or larger) and finally secures the contents with a tuft of glass wool. The test tube is clamped vertically and the activated charcoal is first heated with a burner until it becomes weak red heat. Then the Oxi-Cleaner is warmed up and the gas escaping from the top of the test tube is ignited.

 

Experiment 6: The blast furnace process with Oxi cleaners (brief description)

 

Preparation:If you do not use rust directly, powdered iron oxide (Fe2O3) are granulated beforehand. To do this, you soak it with water glass, spread it out to a 3 mm thick layer, e.g. on a baking sheet, let it dry, remove it from the surface and use a hammer to cut it to the size of a pin. The activated carbon must be annealed before the experiment. Then a rust or iron oxide / activated carbon mixture is produced in a mass ratio of 1: 2.
Execution:In a Duran test tube (18 x 180 mm) you put an Oxi-Cleaner approx. 5 - 6 cm high, over it approx. 2 cm high small pottery shards, then cover approx. 5 cm high with the activated carbon / iron oxide mixture and secure at the end the contents through a tuft of glass wool. The test tube is clamped vertically and first the activated carbon / iron oxide mixture is heated with a burner until it is faintly red heat. Then the Oxi-Cleaner is warmed up and the gas escaping from the top of the test tube is ignited.
After the experiment has ended, the test tube is allowed to cool, the contents poured into a porcelain bowl and checked for appearance and with a magnet. Small iron reguli can be found, these are magnetic.

 

Experiment 7: "Bang effect" with wax (brief description, modified from [1])

In a test tube (16 x 160 mm) you put an Oxi cleaner about one centimeter high, directly on top of it a little glass wool and a piece of candle wax. The test tube is clamped vertically, then the wax and the cleaner are heated at the same time as possible. After a short time, the wax vapors burn violently with a bang.

Danger: Use protective goggles and protective glass, as the test tube can shatter!

 


A sparkler made from "pot sponge wire"

Equipment / chemicals:300 mL Erlenmeyer flask, suitable stopper, stopper (larger than the opening of the Erlenmeyer flask) with hook on the bottom, test tube, suitable pierced stopper with short glass tube, suitable piece of tubing for evacuating the gases, "Hoffmanns Vanish Oxi action®", steel wire (from metal scourers), wood chips, match, sand
Preparation:You put sand about one centimeter high in the Erlenmeyer flask. Then remove three steel wires approx. 20 centimeters long from the pot cleaner and twist them together. One end of the twisted steel wire is attached to the hook of the large plug, and the other end is wound around a halved match three or four times. When you put the stopper on the Erlenmeyer flask, the match must not touch the sand on the floor. Now you put about three grams of "Hoffmanns Vanish Oxi action®" in the test tube, put on the pierced stopper with the glass tube and the connected piece of hose, hold it in the Erlenmeyer flask and then heat the cleaner. The fill level of the piston with oxygen can be determined with the aid of the chip test. When the flask is completely filled with oxygen, it is closed with the appropriate stopper.
Execution:First you try to ignite a steel wire from the pot cleaner with the burner. Then you light the match, remove the appropriate stopper from the Erlenmeyer flask and quickly and loosely put on the large stopper with the twisted steel wires.
Observation:While the steel wire cannot be ignited with a burner in the air, the twisted steel wire in the flask burns like a sparkler with sparks.
Interpretation:The pupils can see that, unlike when comparing the flammability of an iron nail with that of iron wool, the degree of fragmentation is not important as a reaction condition, but the high proportion of oxygen causes the steel wires to burn violently and completely.

 

Experiment 9: Determination of the gas quantities to be released from Oxi products (brief description)

Exactly 0.5 grams of an Oxi product are weighed into a test tube, this is closed with a pierced stopper with a short glass tube and connected to a gas syringe with a short piece of tubing. The Oxi product is then heated until the volume in the gas syringe no longer changes. After cooling down, you can read off the resulting gas volume.

 

 

Equipment / chemicals:2 100 mL piston sampler with stopcock, combustion tube, ∅ inside 6 mm, length 30 cm, short pieces of tubing for connecting piston samplers and combustion tube, test tube 16 x 180 mm, suitable pierced stopper with short glass tube, approx. 30 cm long connecting tube suitable for a gas syringe, short angled glass tube with non-return device, glass wool, Oxi cleaner according to Table 1, copper oxide in wire form, hydrogen
Preparation:The combustion tube is largely and as tightly as possible filled with the copper oxide in wire form and this is secured at both ends with glass wool. A hydrogen bottle is attached to one side and the angled glass tube with kickback protection to the other side. Hydrogen is then allowed to flow through the combustion tube. If the detonating gas sample fails on the angled glass tube, the escaping hydrogen is ignited and the copper oxide is then heated with a burner until it is visibly and as completely as possible reduced to pink copper. The combustion tube is then left to cool in a stream of hydrogen.
If there is no hydrogen cylinder available, natural gas can alternatively be used for the reduction, but the process then takes a little longer.
Execution:Then you fill the test tube about one third with the Oxi-Cleaner to be examined, close it with the pierced stopper and connect it to a piston sampler via the approx. 30 cm long piece of tubing. The hose should not be shorter, because when the cleaner decomposes, some water vapor is generated and this should condense in the hose and not in the gas syringe. The cleaner is then heated with a burner and the gas produced is collected in the gas syringe. The first 100 mL filling is discarded in order to be as sure as possible that the air previously contained in the test tube has been displaced and only the released gas mixture is collected. After the gas syringe has been filled with 100 mL gas for the second time, it is closed and connected to the combustion tube and the second gas syringe using short pieces of tubing. Now you open the tap on the gas syringe with the gas sample again, heat the copper rod with a burner and pass the gas over it several times. The position of the burner should be changed several times. When the copper still contained is no longer oxidized and the gas volume remains constant, the reaction is over. The apparatus is allowed to cool and the remaining gas volume is read off. This experiment is repeated with all the Oxi cleaners to be examined, but the copper oxide must first be reduced again.
Observation:

Depending on the severity of the heating, we obtained the following residual volumes and proportions of oxygen with the Oxi cleaners we examined from 100 mL of captured gas:

productV (gas) (rest)Percentage of oxygen
Dalli Fleck Weg Oxi Power®32 - 40 mL60 - 68 %
Hoffmann's Vanish Oxi action®2 - 8 mL92 - 98 %
Heitmann O2-Energie®2 - 7 mL93 - 98 %
Orange Glo Oxi Clean®4 - 12 mL88 - 96 %

Table 1: Determined proportions of oxygen in 100 mL released gas

Evaluation:On the one hand, the students can see that obviously not only oxygen is released as a gas. On the other hand, "Dalli Fleck Weg Oxi Power®" delivers the most gas. However, this contains only about 60 - 68% oxygen and is therefore obviously not so suitable for experiments in which oxygen as pure as possible is required.

 

Experiment 11: Detection of carbon dioxide in the gas mixtures (brief description)

A test tube is filled about one third with the Oxi-Cleaner to be examined, a pierced stopper with a small glass tube is attached and this is connected to a piece of hose and an inlet tube with an extended tip. This is held in a second test tube with some lime water in it. Now you heat the cleaner and after a while you can observe a slight clouding of the lime water.

 

Experiment 12: Determination of the proportion of carbon dioxide in the gas mixtures

 

Equipment / chemicals:2 100 mL piston samplers with stopcock, 1 250 ml Erlenmeyer flask, 1 matching rubber stopper with two bores, 1 frit, 1 curved glass tube, short pieces of tubing for connecting piston samplers and absorption apparatus, test tube 16 x 160 mm, matching pierced stopper with short Glass tube, approx. 30 cm long connection hose suitable for a gas syringe, Oxi cleaner according to Table 1, potassium hydroxide, w (KOH) = approx. 30%
Execution:

According to experiment 10, 100 ml of the gas samples to be examined are collected, whereby it is also important to discard the first 100 ml filling. Then connect the two gas samplers (one of them with 100 mL of the gas sample to be examined) according to Figure 1 to the Erlenmeyer flask, which is largely filled with 30% potassium hydroxide solution (BLACK's reagent), and pass the gas through the potassium hydroxide solution into the other piston sampler. Then you close the taps, exchange the gas syringe and pass the gas through the potassium hydroxide solution again. This process is repeated a third time, the gas volume should not change any more.


Figure 1: Absorption apparatus for determining the proportion of carbon dioxide in the gas samples

Observation:

With the Oxi cleaners we examined, we obtained the following residual volumes and proportions of carbon dioxide from 100 mL of captured gas:

product V (gas) (rest)Share of carbon dioxide
Dalli Fleck Weg Oxi Power®60 - 68 mL32 - 40 %
Hoffmann's Vanish Oxi action®92 - 98 mL2 - 8 %
Heitmann O2-Energy®93 - 98 mL2 - 7 %
Orange Glo Oxi Clean®88 - 96 mL4 - 12 %

Table 2: Determined proportions of carbon dioxide in 100 mL released gas

Evaluation:

If you compare these values ​​with those from Table 1, it quickly becomes clear that the gas volumes released when the Oxi cleaners are heated, apart from oxygen and carbon dioxide, cannot contain any other gases in significant quantities.

At the same time, the students can see that "Hoffmanns Vanish Oxi action®", "Heitmann O2-Energy® "and" Orange Glo Oxi Clean® "are equally well suited for the experiments presented, while" Dalli Fleck Weg Oxi Power® "contains less oxygen and more carbon dioxide in the gas mixture.

 

[1] www.chemie-baumbach.de, experiment instructions, investigation of the reaction of various alkanes with pure oxygen