Ib Bio Syllabus
OxidatiOn and ReductiOn
OxidatiOn & ReductiOn
9.2
9
Introduction to oxidation and reduction
Redox equations
Some common oxidising agents and reducing agents (EXT)
9.3
Reactivity
9.4
Voltaic cells
19.1
Standard electrode potentials (AHL)
9.5
Electrolytic cells
19.2
cORe
9.1
Electrolysis (AHL)
TOK Are oxidation numbers real?
I remember contemplating on the nature of reality back in Chapters 2 and 4, with regard to electrons and hybridization respectively. The implication always seems to be that reality is in some way desirable.
Maybe my bank account might be a useful analogy to oxidation numbers? At the end of every month there is a number assigned to it, but as the month progresses this number gets smaller and the numbers assigned to the local supermarket, the petrol station, the government etc. all go up. Hardly any of it gets turned into bank notes for me to carry around and even then is a bank note any more real than the number printed on my bank statement. Isn’t the fact that this piece of paper is worth $20 just another, very convenient, shared fiction? Along as we are all happy to share the belief that the figures on my bank statement and the number on my bank notes mean something then real or not these numbers, like
oxidation numbers, are very useful and certainly a lot easier than pushing around wheelbarrows full of gold, or wearing a necklace of sea-shells with holes drilled in them. The whole thing is perhaps closely related to the philosophy of Charles Sanders Peirce, who developed the concept of “pragmatic truth” that in which it was convenient for society to believe; in other words truth is more an attribute of a society than an attribute of the physical world. Are oxidation numbers useful? Certainly they are capable of giving us a definitive answer as to whether in a chemical change, a particular atom is oxidised, reduced, or neither, but is the change any more than
OxidatiOn & ReductiOn
9.2
9
Introduction to oxidation and reduction
Redox equations
Some common oxidising agents and reducing agents (EXT)
9.3
Reactivity
9.4
Voltaic cells
19.1
Standard electrode potentials (AHL)
9.5
Electrolytic cells
19.2
cORe
9.1
Electrolysis (AHL)
TOK Are oxidation numbers real?
I remember contemplating on the nature of reality back in Chapters 2 and 4, with regard to electrons and hybridization respectively. The implication always seems to be that reality is in some way desirable.
Maybe my bank account might be a useful analogy to oxidation numbers? At the end of every month there is a number assigned to it, but as the month progresses this number gets smaller and the numbers assigned to the local supermarket, the petrol station, the government etc. all go up. Hardly any of it gets turned into bank notes for me to carry around and even then is a bank note any more real than the number printed on my bank statement. Isn’t the fact that this piece of paper is worth $20 just another, very convenient, shared fiction? Along as we are all happy to share the belief that the figures on my bank statement and the number on my bank notes mean something then real or not these numbers, like
oxidation numbers, are very useful and certainly a lot easier than pushing around wheelbarrows full of gold, or wearing a necklace of sea-shells with holes drilled in them. The whole thing is perhaps closely related to the philosophy of Charles Sanders Peirce, who developed the concept of “pragmatic truth” that in which it was convenient for society to believe; in other words truth is more an attribute of a society than an attribute of the physical world. Are oxidation numbers useful? Certainly they are capable of giving us a definitive answer as to whether in a chemical change, a particular atom is oxidised, reduced, or neither, but is the change any more than