2.5g of hydrated barium salt gave on heating, 2.13g of the anhydrous salt. Given that the RMM of the anhydrous salt is 208,What is the number of molecules of water of crystallization of the barium salt.
To find the number of molecules of water of crystallization, we first need to determine the molar mass of the water molecules in the hydrated barium salt.
Step 1: Calculate the molar mass of the anhydrous salt.
Given that the Relative Molecular Mass (RMM) of the anhydrous salt is 208, we can directly use this value.
Step 2: Calculate the molar mass of the water molecules.
Since we know the mass of the hydrated salt (2.5g) and the mass of the anhydrous salt (2.13g), we can find the mass of the water lost during heating.
Mass of water lost = Mass of hydrated salt - Mass of anhydrous salt
Mass of water lost = 2.5g - 2.13g = 0.37g
To convert this mass to moles, we need to divide by the molar mass of water (18g/mol).
Number of moles of water lost = Mass of water lost / Molar mass of water
Number of moles of water lost = 0.37g / 18g/mol ≈ 0.0206 mol
Step 3: Determine the number of water molecules.
We know that one mole of a substance contains 6.022 x 10^23 particles (Avogadro's number). Therefore, the number of water molecules lost can be calculated as:
Number of water molecules = Number of moles of water lost x Avogadro's number
Number of water molecules = 0.0206 mol x 6.022 x 10^23 molecules/mol
Now you can calculate the number of water molecules to find the answer to your question.