Topic 3 Flashcards
What is oxidation
Loss of electrons, removable of hydrogen, gain of oxygen
What is reduction
Gain of electrons, addition of hydrogen, loss of oxygen
what happens to an oxidising agent
When it reacts it gains electrons
What happens to a reducing agent
When it reacts it loses electrons
What does disproportionation mean
When the same element has been simultaneously reduced and oxidised
What is the oxidation number for an uncombined element
ZERO
What is the rule of hydrogens oxidation number
It is +1 unless combined with a metal where it changes to -1 as it forms a hydride
What is the rule of oxygens oxidation number
It is -2, except in peroxides where it is -1 and when combined with fluorine where it is +2
What does it mean if the oxidation number of an element has decreased
Reduction has taken place
What does it mean if the oxidation number of an element has increased
Oxidation has taken place
What is the systematic name of Na2SO4
Sodium sulfate (VI)
What is the systematic name of Na2SO3
Sodium sulfate (IV) or it can be called sodium sulfite
Why are the systematic names of Na2SO4 and Na2SO3 different
Na2SO4, sulfate has +6 oxidation number whereas
Na2SO3, sulfate has +4 oxidation number
Equation for chlorine and sodium hydroxide in cold alkaline conditions
Cl2 + 2NaOH –> NaCl + NaClO + H2O
Equation for chlorine and sodium hydroxide in hot alkaline conditions
3Cl3 + 6NaOH –> 5NaCl + NaClO3 + 3H2O
How do you know which side the electrons go on in a redox half equation
Reduction reaction they go on the reactant side, the left
Oxidation reaction they go on the product side, the right
Hot aqueous conditions of chlorine and sodium hydroxide
3Cl2 + 6NaOH- –> 5NaCl- + NaClO3- + 3H2O
Cold aqueous conditions of chlorine with sodium hydroxide
Cl2 + 2NaOH- –> NaClO- + NaCl + H2O
