A 2.000g sample of FeF2 times xH2o is dried in an oven. When the anhydrous salt is removed from the oven, its mass is 0.789g. What is the value of x?
To find the value of x in the compound FeF2 times xH2O, we need to calculate the amount of water lost during the drying process.
1. Calculate the mass of water lost:
Mass of anhydrous salt = 0.789 g
Mass of hydrated salt = 2.000 g
Mass of water lost = Mass of hydrated salt - Mass of anhydrous salt
= 2.000 g - 0.789 g
= 1.211 g
2. Calculate the moles of water lost:
The molar mass of water (H2O) is 18.015 g/mol.
Moles of water lost = Mass of water lost / Molar mass of water
= 1.211 g / 18.015 g/mol
= 0.0672 mol
3. Determine the value of x:
In the compound FeF2 times xH2O, the ratio of FeF2 to H2O is 1: x. This means that 1 mole of FeF2 is always associated with x moles of H2O.
Moles of H2O = 0.0672 mol
Therefore, x = Moles of H2O = 0.0672 mol
So, the value of x is 0.0672.
To find the value of x in the expression FeF2 times xH2O, we need to use the information provided in the question. Here's how you can solve it step-by-step:
Step 1: Calculate the mass of water lost during the drying process.
Mass of the hydrated salt = 2.000g
Mass of the anhydrous salt = 0.789g
Mass of water lost = Mass of the hydrated salt - Mass of the anhydrous salt
= 2.000g - 0.789g
= 1.211g
Step 2: Determine the number of moles of water lost.
Mass of water lost = 1.211g
Molar mass of water (H2O) = 18.015 g/mol
Number of moles of water lost = Mass of water lost / Molar mass of water
= 1.211g / 18.015 g/mol
Step 3: Find the molar ratio between FeF2 and H2O.
By comparing the chemical formula of the hydrated salt and the anhydrous salt, we can determine the molar ratio.
The formula of the hydrated salt is FeF2 times xH2O.
The formula of the anhydrous salt is FeF2.
Since the anhydrous salt is FeF2, it means the x moles of water are lost during the drying process since it went from FeF2 times xH2O to FeF2.
Therefore, the molar ratio of FeF2 to H2O in the hydrated salt is 1: x (1 mol of FeF2 is associated with x mol of H2O).
Step 4: Calculate the value of x.
Since the molar ratio of FeF2 to H2O is 1: x, and we know the number of moles of water lost, we can set up the following equation:
Number of moles of water lost / 1 = Number of moles of water lost / x
Solving for x:
1 / x = (1.211g / 18.015g/mol)
x = 18.015g/mol / 1.211g
x ≈ 14.876
Therefore, the value of x in FeF2 times xH2O is approximately 14.876.