Redox 1 Flashcards
What is oxidation number?
Valency of an element. Number of electrons necessary to make element neutral.
Oxidation number = ?
Charge
Oxidation number of oxygen (mostly)
-2
Exceptions of oxidation number of oxygen
When with fluorine or in peroxide, -1. In superoxides, -0.5.
Oxidation number of fluorine always
-1
Oxidation number of hydrogen
- In hydrides, -1.
What is oxidation?
Loss of electrons
What is reduction?
Gain of electrons
Oxidising agent
Gains electrons, is itself reduced.
Reducing agent
Loses electrons, is itself oxidised.
What is disproportionation?
Element in a single species being simultaneously reduced and oxidised.
Why is oxidation number useful?
Assigning oxidation number to elements allows one to see whether an element has been reduced or oxidised.
Which ions do metal form?
Positive ions by loss of electrons, increase in oxidation number.
Which ions do non-metals form?
Negative ions by gain of electrons, decrease in oxidation number.
What colour is iron (II) and what colour is iron (III)?
Pale green and pale yellow.
