Redox I Flashcards
Oxidation
When a species loses one or more electron
Reduction
When a species gains one or more electrons
Oxidation number
Charge that the element would have if the compounds were fully ionic
Disproportionation
Redox reaction in which an element in a single species is simultaneously oxidised and reduced.
A redox reaction involves
both reduction and oxidations
Give everyday examples of oxidation
burning of fuels
Rusting of ions
Bleaching of dyes
Give everyday example of reduction
extraction of metals
In a redox reaction, the oxidising agents
a species that oxidises another species by removing one or more electrons but itself is reduced
In a redox reaction, the reducing agents
a species that reduces another species by giving it one or more electrons but itself is oxidised
For the oxidising agent Cl 2, what is produced when reduced.
Cl -
For the oxidising agent Br2, what is produced when reduced.
Br -
For the oxidising agent MnO 4-, what is produced when reduced.
Mn 2+
For the oxidising agent Cr2O7 2-, what is produced when reduced.
Cr 3+
For the oxidising agent H2O2, what is produced when reduced.
H2O
For the oxidising agent Fe 3+, what is produced when reduced.
Fe 2+
For the oxidising agent H2SO4, what is produced when reduced.
SO 2
For the oxidising agent HNO3, what is produced when reduced.
NO 2
For the oxidising agent H+ in dilute acids , what is produced when reduced.
H 2
For the reducing agent. I- / HI, what is the product when oxidised?
I 2
For the reducing agent H2S, what is the product when oxidised?
S
For the reducing agent SO2, what is the product when oxidised?
SO4. 2-
For the reducing agent Fe 2+, what is the product when oxidised?
Fe 3+
For the reducing agent H2O2, what is the product when oxidised?
0
For the reducing agent Sn 2+Tin, what is the product when oxidised?
Sn 4+
For the reducing agent Carbon , what is the product when oxidised?
carbon monoxide or carbon dioxide
How does an ionic equation show chemical change?
by showing only the reacting ions and any other reacting atoms or molecules whilst leaving out the spectator ions
What is a half equation?
An ionic equations used to describe either the gain or loss of electrons during a relic reaction
What are oxidation numbers calculated on the basis of?
that bonding electrons are assigned to the more electronegative atom in covalent bond
The ionic half equations can be combined to give
full ionic equations
When writing a half equation for oxidation…
the electrons are seen on the RHS
When writing a half equation for reduction…
the electrons are seen on the LHS
When writing a half equation for complex compounds… what are some rules
“If reaction takes place in acid solution add H+ ions (LHS) + H20 (RHS)
Balance atoms followed by charge to become neutral”
What is the oxidation number of uncombined elements ?
ZERO
What is the oxidation number for monatomic ions?
charge on the ion
What is the oxidation number for group 1 metals?
1+
What is the oxidation number for group 2 metals?
2+
What is the oxidation number for Fluorine?
1-
What is the oxidation number for Hydrogen?
1+
What is the oxidation number for Hydrogen combined with a metal ?
1-
What is the oxidation number for oxygen ?
2-
What is the oxidation number for oxygen in peroxide or superoxides?
depends
What is the sum of oxidation numbers in a neutral compound?
zero
What is the sum of oxidation numbers in a polyatomic ion?
1-
Do all elements have fixed oxidation numbers?
no only some
How do metal elements form positive ions?
when their atoms react by loss of electrons with an increase in oxidation number
How do non-metal elements form negative ions ? The
when their atoms or molecules react by gain of electrons with a decrease in oxidation numbers
How are compounds of an element classified?
Into oxidation states
