Acids:
- taste sour when they are eaten
- can sting the skin when they are touched
- can corrode (or eat away at) metals and skin
- can be used as a reactant during electrolysis due to the presence of mobile ions
- turn blue litmus paper red
- are studied in chemistry and biology
- turn red or orange on universal indicator
Bases (Alkalis):
- Bitter taste (opposed to sour taste of acids)
- Slimy, or soapy feel on fingers
- Many bases react with acids and precipitate salts.
- Strong bases may react violently with acids. An acid spill can be safely neutralised by using a mild base.
- Bases turn red litmus paper blue
- Bases are substances that contain metal oxides or hydroxides
- Bases which are soluble in water form alkalis (soluble bases)