Step 1: Calculate the molar mass of water.
The molar mass of water is 18.015 g/mol.
Step 2: Calculate the number of molecules in .413 moles of water.
To calculate the number of molecules in .413 moles of water, multiply the molar mass of water (18.015 g/mol) by .413 moles of water.
Answer: The number of molecules in .413 moles of water is 7.37195 molecules.