416g of anhydrous barium chloride was obtained when 488g of the
hydrated salt was heated. (formula of the hydrated salt is BaCl 2 .nH 2 O)
To find the value of "n" (the number of water molecules in the formula of the hydrated salt BaCl2.nH2O), we need to calculate the amount of water lost during heating.
1. Determine the molar mass of anhydrous barium chloride (BaCl2) and hydrated barium chloride (BaCl2.nH2O).
- Molar mass of BaCl2:
- Barium (Ba) atomic mass = 137.33 g/mol
- Chlorine (Cl) atomic mass = 2 * 35.45 g/mol = 70.90 g/mol
- Total molar mass of BaCl2 = 137.33 + 70.90 = 208.23 g/mol
- The molar mass of hydrated barium chloride (BaCl2.nH2O) will be greater due to the added water molecules.
2. Calculate the molar mass difference between hydrated and anhydrous barium chloride.
- Molar mass difference = molar mass of hydrated barium chloride - molar mass of anhydrous barium chloride
- Molar mass difference = 208.23 g/mol (from step 1) - ?? g/mol (unknown)
3. Determine the number of moles of anhydrous barium chloride obtained.
- Moles of anhydrous barium chloride = mass of anhydrous barium chloride / molar mass of anhydrous barium chloride
4. Determine the number of moles of hydrated barium chloride lost.
- Moles of hydrated barium chloride lost = Moles of anhydrous barium chloride obtained
5. Calculate the mass of water lost during heating.
- Mass of water lost = Moles of hydrated barium chloride lost * molar mass difference
6. Determine the number of water molecules (n) in the formula BaCl2.nH2O.
- Number of water molecules (n) = Mass of water lost / molar mass of water
By following these steps, you can calculate the value of "n," the number of water molecules (H2O) in the formula BaCl2.nH2O.