Solubility of AgI in water is 2.1×10-6g/L. Solubility product Ksp of saturated solution of AgI is obtained C=(2.1×10-6)/235=8.94×10-9mol/L Why is C equal to S/M? Look out for confusion

Solubility of AgI in water is 2.1×10-6g/L. Solubility product Ksp of saturated solution of AgI is obtained C=(2.1×10-6)/235=8.94×10-9mol/L Why is C equal to S/M? Look out for confusion

The ionization equilibrium of silver iodide is:
AgI=Ag++I-
Ksp=c (Ag+).c (I-)
However, the solubility of AgI in water is 2.1×10-6g/L, which is converted into the concentration of substance.
C=(2.1×10-6)/235=8.94×10-9mol/L
So Ksp=(8.94×10-9)×(8.94×10-9)=7.15×10-17
That's weird. What's the right way? It turns out it's different from my textbook?
The textbook is 8.3×10-17. Are you mistaken about the solubility of AgI in water?
That's because
C=n/V=m/(M.V). Since you have given the condition that the solubility of AgI in water is 2.1×10-6g/L, it is calculated by default under the condition of 1 there is the above algorithm, which is the default in the book.

Before and after the chemical reaction, whether the types of elements and substances will change

Chemical change is essentially the breaking of old bonds and the formation of new bonds, the conversion or transfer of atoms or electrons between molecules in contact with each other, and the formation of new molecules accompanied by changes in energy! That is, new matter is produced and elements do not change.

Chemical change is essentially the breaking of old bonds and the formation of new bonds, the conversion or transfer of atoms or electrons between molecules in contact with each other, and the formation of new molecules accompanied by changes in energy! There is a new substance, and the elements do not change.