Final answer:
To find the value of X for the hydrated compound NiSO4 · XH2O, subtract the mass of the anhydrous compound from the initial mass to get the mass of water lost (2.00 g). Then, divide by the molar mass of water (18.02 g/mol) to determine the moles of water, which is equal to X.
Step-by-step explanation:
To determine the value of X in the hydrated compound NiSO4 · XH2O, we must calculate the difference in mass before and after heating to find the mass of the water lost. In this case, the mass of the hydrated nickel sulfate is reduced from 4.14 g to 2.14 g upon heating. The difference in mass, 2.00 g, is the mass of the water that was initially present in the compound.
We know the molar mass of water, H2O, is 18.02 g/mol. To find the number of moles of water that corresponds to the lost mass, we divide the mass of the water by its molar mass:
Number of moles of water = 2.00 g ÷ 18.02 g/mol
This calculation gives us the moles of water, which is equal to the coefficient X in our hydrated compound's formula. Since the molar mass of anhydrous NiSO4 is not necessary to determine X, it's not included in the calculation.
Therefore, by dividing the mass of the water by its molar mass, we obtain the moles of water, which corresponds to the value of X in the hydrated compound NiSO4 · XH2O.