Redox Flashcards
what is a reducing agent
a substance that is oxidised in order to reduce another substance
what is an oxidising agent
a substance that is reduced in order to oxidise another substance
What could happen when a substance is oxidised?
Addition of oxygen,
loss of hydrogen or the
loss of electrons.
what could happen when a substance is reduced?
loss of oxygen,
addition of hydrogen or the
gain of electrons.
what is the oxidation state of an element on its own?
any element on its own has an oxidation state of 0.
what is the oxidation state of a simple ion
for a simple ion the oxidation number is the charge on the ion
what is the oxidation state of hydrogen in the compound NaH
The hydride ion in NaH has an oxidation state of -1
what is the oxidation state of oxygen in the compound H2O2
the oxidation state of oxygen is -1 in hydrogen peroxide
what is the oxidation state of oxygen in the compound F2O
The oxidation state of oxygen is +2 in oxygen difluoride
what is the sum of the oxidation numbers in a compound?
The sum of oxidation numbers in a compound is 0
What is the natural oxidation number of oxygen as an ion?
The oxidation number of oxygen is -2 ( still a 0 as an atom or molecule)
What is the natural oxidation number of Hydrogen as an ion
The oxidation number of Hydrogen is +1 (still a 0 as an atom or a molecule)
What is the natural oxidation number of the fluoride ion
-1
What is the oxidation number of a complex ion e.g(so4)
The oxidation number of a complex ion is the sum of the oxidation numbers of the constituent ions.
e.g in so4^2- -2=-8+6
How do you balance a redox equation
- Work out the formulae of the species in the reaction before and after the reaction don’t forget to balance)
2.work out the oxidation states of an element on both sides of the equation
- add electrons to a side to balance the oxidation states of both sides
- add H+ ions to balance the charges on both sides
- And if that doesn’t work add sufficient water molecules to balance the equation.
