Redox (Physical) (conplete) Flashcards
Define - Oxidation state.
Name how the range of oxidation states is found/limited.
- The charge of an ion or a theoretical charge of an atom in a covalently bonded compound assuming the bond becomes ionic.
- The range of oxidation states is limited to the position of an element on the periodic table.
Name the 5 rules of naming Oxidation states.
1 - On simple ions, the oxidation state is the charge on the ion.
2 - In elements the oxidation state is always zero.
3 - The total of all the oxidation states must always be equal to the overall charge on the species.
4 - In molecules and more complex ions, the more electronegative element is assumed to be the negative ion.
5 - H is nearly always +1 and oxygen -2
- (exceptions: hydrides (e.g: NaH; Na=+1 H= -1) and peroxides (e.g: H202; H=+1 O= -1)
Name the 6 steps into writing Half equations.
1 - Calculate the oxidation states on each side of the equation.
2 - Balance the element changing oxidation state.
3 - Sort out the number of electrons needing to be added on the necessary side.
4 - Sort out the number of O’s. For every O gained/lost, add/remove one H20 molecule onto the other side.
5 - Sort out the number of H’s. For every H gained/lost, add/remove one H+ ion on the other side.
6 - Check if the total electric charge on the left = the right.
Name the steps into combining half equations.
1 - Ensure each reaction equation is going the favourable direction.
2 - Balance the number of electrons so the co-efficients are equal in both equations.
3 - Combine the equations, cancelling out the electrons on each side, and cancelling any other molecules/ions that can be on each side.
Define what a disproportionation reaction is.
- Where during a reaction there is a species that is both oxidised and reduced.