Answer:
NiCl₂·4H₂O, its name being nickel (II) chloride tetrahydrate.
Step-by-step explanation:
The constant mass achieved after heating is the mass of anhydrous nickel (II) chloride, NiCl₂. While the mass lost was water.
- Mass lost = 1.167 g - 0.750 g = 0.417 g
Now we convert 0.750 g of NiCl₂ into moles, using its molar mass:
- 0.750 g NiCl₂ ÷ 129.6 g/mol = 0.0058 mol NiCl₂
Then we convert 0.417 g of H₂O into moles:
- 0.417 g H₂O ÷ 18 g/mol = 0.0231 mol H₂O
With the above information we can calculate that the number of H₂O moles is 4 times higher than the number of NiCl₂ moles.
Meaning that the formula of the hydrate is NiCl₂·4H₂O, its name being nickel (II) chloride tetrahydrate.