Redox reactions Flashcards
What happens in a precipitation reaction?
Cations and anions come together in a solution, to form insoluble ionic compound
What happens in neutralisation reaction?
reactions, H+ and OH- come together to form water
What happens in Reduction oxidation (redox reaction)?
Electrons are transferred between species (molecules, ions or atoms) reactants
why is it called redox oxidation?
These reactions occur at the same time, cannot have reduction without oxidation.
One component with with reduce and the other oxidised
why is it called redox oxidation?
These reactions occur at the same time, cannot have reduction without oxidation.
One component with with reduce and the other oxidised
What is Redox oxidation
When a atom, ion or molecule ions loses electrons (becomes more positively charged)
LOSS OF ELECTRONS
Oxidation is used because the first reactions of this type to be studied involved oxygen and many metal react with oxygen to form metal oxides.
What is redox reduction?
as the sodium metal is oxidized, oxygen is transformed from neutral O2 to two O-2 ions.
When an atom, ion or molecule has become more negatively charged (gained electrons) it has been reduced.
GAIN OF ELECTRONS = reduction
What does OILRIG mean?
Oxidation is Loss, Reduction is Gain of electrons
What is oxidation numbers?
a measure of the degree of oxidation of an atom in a substance compared to its elemental state
What is the first basic rule of Oxidation number
can be positive, zero or negative
all elements have oxidation number of zero.
What is the second basic rule of Oxidation numers?
Oxidation number of a monatomic ion is the same as its charge
Ag+ = +1
Cl- = -1
Fe2+ = +2
Fe3+ = 3+
How do you tell the difference between charge and oxidation state?
Charge is number followed by the sigh Fe^3+
Oxidation state is the sign first and followed by number Fe^+3
What is rule number 3 of oxidation numbers?
non-metals usually have negative oxidation numbers, though they may be positive.
a. oxidation number of Oxygen is usually -2.in both ionic and molecular compounds. (Exception for peroxides O2 ^2- oxidation number = –1)
b. Oxidation number of H is +1 when bonded to nonmetals and –1 when bonded to metals (hydrides).
What is the rule number 4 of oxidation numbers?
Sum of oxidation numbers must be zero for a neutral compound, and equal to the charge of a polyatomic ion.
Oxidation numbers are not just the charge! Oxidation number also accounts for covalent bonds, not just ionic compounds.
How do we go about giving oxidation numbers to atoms in molecules and polyatomic ions?
The more electronegative atom is assigned the electrons in a covalent bond
