The number of water molecules in a 1.00L bottle of water can be calculated using the following steps:
Calculate the mass of water in the bottle using the density of water:
density of water = 1.00 g/mL
mass of water = volume of water x density of water
mass of water = 1.00 L x 1000 g/L x 1.00 g/mL
mass of water = 1000 g
Convert the mass of water to moles:
moles of water = mass of water / molar mass of water
moles of water = 1000 g / 18.0 g/mol
moles of water = 55.56 mol
Convert the moles of water to the number of water molecules:
number of water molecules = moles of water x Avogadro's number
number of water molecules = 55.56 mol x 6.022 x 10^23 molecules/mol
number of water molecules = 3.34 x 10^25 molecules
Therefore, there are approximately 3.34 x 10^25 water molecules in a 1.00L bottle of water.