I suppose that you think to 18 kgp: the meaning is a metal "plated with 18 karat (75 %) gold".
It is not 18 kg it is 18 carrat
It is Gold 18 ct
It will decrease the Ksp
rolled gold plated
This means that the jewelry is gold plated with 18 karat gold. You can get different kinds of gold in your jewelry.
It is not 18kcp. Correct is 18KGP - it is mean 18 karat gold plate.
18k white gold
for Ni(OH)2, Ksp=6.0*10^(-16)
ksp = [Ca+2][OH-]^2
No. Ksp can be used for metals as well, such as lead (Pb). The Ksp for Pb is often very small, but increases with increasing temperature.
Ion product < Ksp Unsaturated solution Ion product = Ksp Saturated solution Ion product > Ksp Supersaturated solution
925 means 22kt gold or 18 kt gold
24 Karat Gold .