Redox I Flashcards
(22 cards)
What is an oxidation number
The number of electrons an atom uses to bond with any other atom
What is the oxidation number
of an uncombined element
such as C, H, O 2
0
What is the oxidation number
of combined oxygen
such as H2O
-2
What is the oxidation number of oxygen in peroxides
-1
What is the oxidation number of combined Hydrogen
such as
in NH 3 , H 2 S
+1
What is the oxidation number
of combined hydrogen in metal
hydrides
such as LiH
-1
What is the oxidation number of a simple ion
Charge on the ion
What is the oxidation number of combined fluorine such as in NaF, CaF 2
-1
When an element has more than one stable oxidation number how is it indicated
Written as a Roman numeral
What is the oxidation number of Fe in iron (III) chloride
+3
What are oxyanions
Negative ions that have an element along with oxygen
What is the oxidation number of S in SO 4(2-)
+6
Define oxidation(in terms ofelectron transfer and oxidation
number)
● Loss of electrons
● An increase in oxidation number
Define reduction (in terms of electron transfer and oxidation
number)
● Gain of electrons
● A decrease in oxidation number
What is a redox reaction
A reaction in which both oxidation and
reduction takes place
What is the oxidation number of a metal
0,
because it is an uncombined element
What is an oxidising agent
Species that gains electrons
What is a reducing agent
Species that lose electrons.
What is the oxidation state of chlorine in NaClO
+1
Define the term disproportionation
Where in a redox reaction,
the oxidation states of atoms of the same element increase for some atoms
whereas decrease for some atoms.
Why is, 2CrO 4 2- + 2H +
→ Cr2O72- + h2O,
not a redox reaction?
Chromium is oxidised whereas
hydrogen remains the same
oxidation state (no element is
reduced
