pH & Indicators (chpt. 18) Flashcards
1
Q
Limitations of pH scale
A
- limited to 0-14 even though outside values are possible
- does not work with very concentrated solutions
- limited to aqueous solutions yet chemical reactions can occur in other types of solution
2
Q
Define pH
A
Negative log to the base 10 of the hydrogen ion concentration measured in moles per litre
(or write out)
3
Q
Conjugates - relative strength of acids & bases
A
The stronger the acid the weaker its conjugate base (and reverse)
4
Q
*Calculations
A
5
Q
Acid-base indicator
A
A substance that changes colour according to the pH of the solution in which it is placed
6
Q
Range of an indicator
A
The pH interval over which there is a clear change of colour for that indicator
7
Q
What does it mean that the end point of a titration must be sharp
A
A very small addition of acid or base (one drop) must cause a complete colour change in the indicator
