Hi everybody

Can someone help me with this question please?

(I apologise if there are mistakes, English is not my mothertongue

)

The hydrated nickel (II) chloride (NiCl2.xH2O) is a green crystalline solid. Heavily heated, a 0.238g sample of this compound dehydrates.

What is the value of x knowing that there remains 0.130g of solid after heating?

Answer:6

Okay so I substracted 0,130g to 0,238g which gives me 0,108g of water. With this and the molar mass, I can easily find the mole number: 6*10^-3. But I Don't really understand know what I have to do