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Hydrogen peroxide acts as both an oxidizing and reducing agent, because the oxygen freed in decomposition readily combines with other substances. Its oxidizing properties are used in bleaching thing such as hair, feathers, ivory and delicate fabrics e.g. wool, silk, nylon etc. that would be destroyed by other agents. In a different form, it can be used as an antiseptic or a throatwash. It restores the original colour in paintings, by oxidizing the black lead sulfide to white lead sulphate. It can also be used as a source of oxygen in the fuel mixture for many rockets and torpedoes. So on the whole, Hydrogen peroxide is a very useful substance.
Catalysts
A catalyst, in chemistry is any substance that increases the rate of reaction without being changed itself. Enzymes are naturally occurring catalysts, responsible for many bio – chemical reaction. Gas catalysts and those in liquid form are usually used in their pure forms or in combination with suitable solvents. Solid catalysts are commonly dispersed into other substances that are called catalyst supports. But the one I am looking at is metal oxides as catalysts. Most solid catalysts are metals or the oxides, sulfides and halides of metallic elements and of the semi – metallic boron, aluminum and silicone.
Prediction
I predict that the metals in the S-block of the periodic table would be a more efficient catalyst, followed by the metals in the P-block then the D-block, this is shown in a reactivity series, metals in the S-block has an electron configuration ending with two electron on the out er most shell, where as metals in te p block has
Fair test
The size of the beaker must be the same as so the measuring cylinder, as the surface area must remain the same. The amount of metal oxide must stay the same (1.0g) otherwise the experiment would be unfair.
Safety
Safety is very important and it is necessary to follow safety procedures when doing any experiment. Eye protection must be worn such as goggles, not following this safety rule may result in hazardous chemicals contacting with the skin or eyes. Long hair and objects must be tied back. Extra care should be taken because of the corrosive chemicals, which you are working around such as hydrogen Peroxide. A lab coat should also be worn in case any spillage falls onto your clothes.
To avoid any accidents the apparatus should be set up correctly, it should also be set up in a suitable place such as the middle of the lab table.
The solutions should be labelled correctly and the lids of the solutions should are placed on the right bottles and should be secured tightly on
It’s important to use the minimum and only required amounts of the solution, this is done to avoid spillages and the waste of the chemicals.
All the apparatus should be securely fastened into place such as the burette attached to the clamp, and the clamp to the stand. The chemical that we will use is hydrogen peroxide and the metal oxides.
Equipment:
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Conical Flask 250cm3
- Delivery tube
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Measuring Cylinder 500cm3
- Hydrogen Peroxide
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Metal oxides, CaO, MgO, Al2O3 MnO2, Fe2O3, CuO and ZnO
- Scale
- Pipette
- Clamp and stand
- Container A
Cao 2mgo Al203 zno fe0 cuo mno2
Scaling down
2H2O2 (l) → 2H2O(l) + O2 (g)
1dm3 10dm3
1000cm3 10,000cm3
Multiply by 40
100 10,000
40 40
=25cm3 =250cm3
Method
- Set up the apparatus exactly as shown above. Make sure that the equipment is set out in the middle of the table, so there is plenty of room for you to work with.
- The 250cm3 conical flask should be filled with exactly 100cm3 of distilled water, this can be done by using a measuring cylinder. The bottom of the meniscus must lie on the bottom of the measuring scale.
- Fill the container A with ¾ of normal water.
- Fill the 250cm3-measuring cylinder with normal tap water fully. With one hand on the top of the open space of the measuring cylinder place it into container A. to hold this in place a clamp and stand should be used.
- Using a pipette remove some of the water from the measuring cylinder until the bottom of the meniscus lays on the 500cm3 mark, this can be done by squeezing the pipette while its under the measuring cylinder.
- Weigh 1g of the specific metal oxide you are testing by placing the metal on a weighing scale.
- Remove the stopper from the conical flask and add the metal oxide to the distilled water, then quickly replace the stopper.
- Wait until all the gas has been give off and the experiment has finished.
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Record the final volume.