The oxitation state of Cl2 = 0, because the oxidation state of an atom alone or a molucule with one kind of atom is always 0.
The
oxidation state of Cl in HClO is +1 because the oxidation state of H is
+ 1, the oxidation state of O is - 2, and the molecule is neutral, so
+1 + 1 - 2 = 0
The oxidation state of Cl in HCl is - 1, because the oxidation state of H is +1 and the molecule is neutral, so - 1 + 1 = 0.
Also,
you shall remember that when an atom increases its oxidation state is
is oxidized and when an atoms reduces its oxidations state it is
reduced.
With that you conclude that the right option is the last statement: </span>Cl
has an oxidation number of 0 in Cl2. It is then reduced to CI- with an
oxidation number of –1 in HCl and is oxidized to Cl+ with an oxidation
number +1 in HClO.
Yes it is available. It will continue catalyzing the reactions until it becomes completely consumed. That's how enzymes work. They work and are eventually consumed in the process completely without altering the reaction in any way other than speeding it up. <span />