Acid and Alkalis
Some compounds react with water to produce acidic or alkaline solutions
- Acids (Proton donors) - Hydrogen ions
- Alkalis (Proton acceptors) - Hydroxide ions
Strong acid or alkali completely ionises in water (H+).
- Hydrochloric, Sulphuric and Nitric are strongly acidic
- Sodium hydroxide and Potassium hydroxide are strongly alkali
Concerntration of H+ = 1mol/dm cubed
Weak acid or alkali only partially ionises in water (OH-).
- Ethanoic, Citric and Carbonic are weakly acidic.
- Ammonia solution is weakly alkali.
Concerntration of H+ = much less than 1mol/dm cubed
Titrations find out how much acid is needed to neutralise an alkali.
Choosing an indicator:
- Strong acid + strong alkali - any indicator
- Strong acid + weak alkali - menthyl orange
- Strong alkali + weak acid -…