- Classify oxides as either acidic or basic, related to the metallic and non-metallic character of the other element in the oxide.
Oxides are compounds of metals or non-metals with oxygen.
Most metal oxides are basic oxides. Examples include calcium oxide, zinc oxide and magnesium oxide.
- Basic oxides react with acids to form a salt and water (the basic neutralisation reaction).
Basic oxide + acid —–> salt + water
calcium oxide (basic oxide) + hydrochloric acid (acid) —> calcium chloride (salt) + water
- Basic oxides do not react with alkalis
- Many basic oxides do not react with water. However, those from the group I and group II in the periodic table react with water to form a metal hydroxide. An alkaline solution is formed.
Basic oxide + water ——-> metal hydroxide
barium oxide (basic oxide) + water —–> barium hydroxide (metal hydroxide)
Most non-metal oxides are acidic oxides. Examples include sulfur dioxide, carbon dioxide and silicon dioxide.
- Acidic oxides react with alkalis to form salt and water (neutralisation again)
Acidic oxide + alkali —–> salt + water
carbon dioxide (acidic oxide) + sodium hydroxide (alkali) —> sodium carbonate (salt) + water
- Some acidic oxides react with bases such as metal oxides when heated.
Acidic oxide + base —heat—> salt
SIlicon(IV)oxide (acidic oxide) + calcium oxide (base) —heat—-> calcium silicate (salt)
- Many acidic oxides react with water to form acidic solutions.
Acidic oxide + water—–> acid
sulfur trioxide (acidic oxide) + water —-> sulfuric acid (acid)
- Further classify some other oxides as neutral, given relevant information.
Some oxides are neither basic or acidic- they are neutral oxides. They don’t react with acids or bases. Examples of neutral oxides include nitrous oxide (N2O) and carbon monoxide (CO).
Notes submitted by Lintha
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2 thoughts on “C8.2 – Types of Oxides”
We did not finish learning/studying this unit in school before study leave. However, after reading the notes posted above, I understand practically everything (necessary)about the unit! I just wanted to say thank you so much for the notes, this website is truly amazing and an exam saver for students, I am very grateful. Thank you once again 🙂
So glad to hear it Ananya!! 😃 You’re welcome!