ES.2 Flashcards
Oxidation states and redox
What are the three defintions for oxidation?
- The gain of oxygen.
- The lose of electrons.
- An increase in oxidation state.
What are the three defintions for reduction?
- The lose of oxygen.
- The gain of electrons.
- A decrease in oxidation state.
What does the oxidation state of an element in a chemical tell you about that element?
It tells you how many electrons have been lost or gained compared to the unreacted element.
What is the oxidation state useful for in chemistry? (4p)
- Naming inorganic compounds.
- Deciding what has been oxidised and what has been reduced in a redox reaction.
- Identifying oxidising agent and reducing agent in a redox reaction.
- Balancing a redox reaction.
What is the oxidation state of an element that is in its elemental form?
0.
What is the oxidation state of a simple ion?
The same as the charge of that ion.
What should the sum of all the oxidation states in a compound equal to if the compound doesn’t have an overall charge?
0.
What should the sum of all the oxidation states in a complex ion equal to?
The overall charge of that complex ion.
What is the oxidation state of oxygen in a compound, normally?
-2, unless combined with F or in peroxide (-1).
What is the oxidation state of hydrogen in a compound, normally?
+1, unless in metal hydride (-1).
What is the oxidation state of fluorine in a compound?
-1.
What is the oxidation state of chlorine in a compound, normally?
-1, unless combined with O or F.
What is the oxidation state of bromine in a compound, normally?
-1, unless combined with O, F or Cl.
What is the oxidation state of iodine in a compound, normally?
-1, unless combined with O, F, Cl or Br.
What is the oxidation state for group 1 metals in a compound?
+1.
