Naming

[Jasmin Argueta 1K]

For the compound potassium tetracyanonickelate (II) How do you know how many K's you're suppose to put outside the brackets and why does it go in the beginning rather than end.

[Niveda_B_3I]

We know that potassium has a +1 charge, and we know that cyano has a -1 charge and there are 4 cyano so there's a -4 charge but nickelate has a +2 charge so in general the anion has a -2 charge. So there has to be 2 potassium ions so that it is a neutral compound.

[Matthew Mar 1J]

Also, the potassium comes first because it is the cation. Think of the coordination compound as just a really big, really complicated salt. You could consider NaCl where Na is the cation which always comes before Cl, the anion. In this instance (K2)+2 is the cation and [Ni(CN)4]-2 is the anion (hence the negative charge).

[MichelleRamirez_2F]

You have to see what the charge would be on the compound to figure out how many potassium molecules would neitralize that charge.