1. Find the molar mass of CuSO4.5H2O:
* Cu: 63.55 g/mol
* S: 32.06 g/mol
* O (in CuSO4): 4 * 16.00 g/mol = 64.00 g/mol
* H2O: 5 * (2 * 1.01 + 16.00) g/mol = 90.05 g/mol
Total molar mass of CuSO4.5H2O = 63.55 + 32.06 + 64.00 + 90.05 = 249.66 g/mol
2. Calculate the moles of CuSO4.5H2O:
* Moles = mass / molar mass
* Moles = 20 g / 249.66 g/mol = 0.0801 mol
3. Determine the moles of water molecules:
* Since there are 5 moles of water molecules for every 1 mole of CuSO4.5H2O, we have:
* Moles of H2O = 0.0801 mol CuSO4.5H2O * (5 mol H2O / 1 mol CuSO4.5H2O) = 0.4005 mol H2O
4. Convert moles of water to number of molecules:
* Avogadro's number: 6.022 x 10^23 molecules/mol
* Number of H2O molecules = 0.4005 mol * (6.022 x 10^23 molecules/mol) = 2.41 x 10^23 molecules
Therefore, there are approximately 2.41 x 10^23 water molecules in 20g of CuSO4.5H2O.
