Household goods that are bases. Image credit MediaWiki
ZIMSEC O Level Combined Science Notes: Introduction to Bases
- Bases are different from acids
- When a base dissolves in water it makes an alkaline solution
- Metal oxides are bases
- They dissolve in water to form alkaline solutions
- These solutions are also known as alkalis
- Non-metal oxides dissolve in water to form acidic solutions for example carbon dioxide dissolves in water to form carbonic acid (acid rain)
- Alkaline (base) solutions turn litmus paper blue
- They turn Universal indicator green, blue, purple or green
- They do not have a sour taste
- They do not fizz/effervesce when mixed with baking soda
| Acids | Bases |
|---|---|
| Have a sour taste | Do not have a sour taste |
| Turn litmus paper red | Turn litmus paper blue |
| Effervesce/Fizz when mixed with sodium carbonate/sodium hydrogen carbonate (baking soda) | Do not effervesce/Fizz when mixed with sodium carbonate/sodium hydrogen carbonate (baking soda) |
| Turn Universal Indicator: red, orange or yellow | Turn Universal indicator: green, blue or purple |
To access more topics go to the Combined Science Notes page.
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