Convert mass of CuSO4 to moles. Use the molar mass of CuSO4 * 5H2O (249.7 g/mol).
The Correct Answer and Explanation is:
To convert the mass of CuSO4 * 5H2O to moles, you can use the formula: moles=mass (g)molar mass (g/mol)\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}moles=molar mass (g/mol)mass (g)
Step 1: Identify the molar mass of CuSO4 * 5H2O.
The molar mass of CuSO4 * 5H2O is provided as 249.7 g/mol. This is the total mass of one mole of copper(II) sulfate pentahydrate.
Step 2: Find the mass of CuSO4 * 5H2O.
Let’s say you have a specific mass of CuSO4 * 5H2O. For example, if you have 10.0 g of CuSO4 * 5H2O, you can substitute this value into the formula: moles of CuSO4 * 5H2O=10.0 g249.7 g/mol\text{moles of CuSO4 * 5H2O} = \frac{\text{10.0 g}}{\text{249.7 g/mol}} moles of CuSO4 * 5H2O=249.7 g/mol10.0 g
Step 3: Calculate the moles.
Performing the division: moles=10.0249.7≈0.0400 moles\text{moles} = \frac{10.0}{249.7} \approx 0.0400 \text{ moles}moles=249.710.0≈0.0400 moles
Step 4: Conclusion
So, for a 10.0 g sample of CuSO4 * 5H2O, the number of moles would be approximately 0.0400 moles. This conversion is important in stoichiometric calculations because it allows you to relate the mass of a substance to the number of particles (atoms, molecules, or ions) it contains.
Always remember that the molar mass accounts for the masses of all elements present in the compound, including the water molecules in the hydrate. For CuSO4 * 5H2O, the molar mass includes copper, sulfur, oxygen, and the five water molecules.
