The stirring breaks it up faster, the amount of water doesn’t effect it, it just gives it space to spread/dissolve - I think.
There are six atoms of oxygen in that compound.
The cyanide is

A carbon atom has 4 valance electrons and nitrogen has 5. Below is a Lewis-dot-structure of cyanide.
:N≡C.
The carbon atom is still one electron short of having a full octet and so it will seize another electron from almost anything, making the cyanide ion negative and whatever it took the electron from it now positive.
Answer:
10.4
Explanation:
-log(4.2x10^-11) = 10.37 = 10.4
The last one is the suns energy