Did you know?
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 Nitrous oxide has the chemical formula N2O, and is commonly known as “laughing gas” since it produces euphoria when inhaled in small amounts. A major use of nitrous oxide is as an anaesthetic in surgery and dentistry. It is also used in making certain canned pressurized foods, such as canned instant whipped cream, and in motor racing as an oxidizer to increase the power output of engines. |
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Oxygen is the most abundant element on earth. It is a major component of the earth’s crust as well as being about 89% of the mass of all water and about 20% of the air by volume.
When an element or compound combines with oxygen, it is called an oxidation reaction. One of the products of such a reaction is an oxide.
There are two categories of oxides:
- metal oxides
- non-metal oxides
Chemically, oxides are compounds that contain oxygen in the O-2 form. So, Na2O would be an oxide (sodium oxide) but Na2O2 is not considered an oxide (sodium peroxide) since its oxygen is in the O– form.
Metal Oxides
When combined with oxygen, metals will form oxides. For iron, metal oxides are commonly referred to as rust. However, copper can also “rust” and its oxide is green.
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| A rusted chain is an example of iron(III) oxide. | The green roof of the Parliament Buildings in Ottawa is an example of copper(II) oxide. |
Watch this time-lapse video of metal rusting!
Most metal oxides are ionic compounds that react with water to form hydroxides, and are called basic oxides.
Did you know?
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Nitrogen dioxide is a component of smog and forms when nitrogen and oxygen combine in the air. |
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Non-Metal Oxides
Non-metals also combine with oxygen to form oxides. Non-metal oxides tend to be gases, liquids or low-melting solids. Common examples of non-metal oxides are carbon dioxide (in air), nitrogen dioxide (in smog) and sulphur trioxide (pollutant that causes acid rain).
An orange cloud of smog caused in part by NO2
Non-metal oxides react with water to form acids, so they are called acidic oxides.
Check Your Understanding
Answer will be under the assignment section below!!
1. Which one of the following oxides is considered to be acidic?
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- CaO
- SrO
- CO2
- Na2O
2. Is the following statement true or false?
Copper(II) oxide is more acidic than carbon dioxide.
3. Is the following statement true or false?
Phosphorus pentoxide is more basic than sulphur trioxide.
Assignment: Oxide Presentation
**Individual Task – not a group!!! BY YOURSELF!!
Oxides have many different uses. Although many of them are considered negatively, oxides are essential to us. In this activity, you will conduct research into an oxide. .
Once you have completed your research, create a presentation (be as creative as you like – in which ever tool you would like to use) and submit your presentation to the dropbox (which will be available soon in Teams!). If it is a virtual presentation (through prezi or another app) be sure to include the url address!
You may choose one of the following oxides as your topic. You can also find another oxide if you prefer. Sign up for your topic on the front board!
Possible topics:
- greenhouse gasses (CO2)
- smog (NO or NO2)
- rust (Fe2O3)
- sulphur dioxide (SO2) or sulphur trioxide (SO3)
- hydrogen oxide (H2O)
- lithium oxide batteries (Li2O)
- hematite (Fe2O3), used as a pigment in mediaeval manuscripts
**Answers to the above questions….
1. Which one of the following oxides is considered to be acidic?
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- CaO
- SrO
- CO2
- Na2O
2. Is the following statement true or false?
Copper(II) oxide is more acidic than carbon dioxide.
**False – The copper(II) oxide is more basic than carbon dioxide.
3. Is the following statement true or false?
Phosphorus pentoxide is more basic than sulphur trioxide.
**False – The copper(II) oxide is more basic than carbon dioxide.