Answer:
58
Step-by-step explanation:
64 fl. oz H2O * 0.0295735296 L/fl. oz = 1.9 L H2O
Then, using the density of water, 1 g/cm^3, and the fact that 1 mL = 1 cm^3 we can find:
1.9 L H2O * 1000 mL/L * 1 cm^3/mL * 1 g/cm^3 = 1900 g H2O
Making the final conversion using the molar mass of H2O, 33.008 g/mol:
1900 g H2O * 1 mol/ 33.008 g = 58 mol H2O
1 mole is equal to Avagadro's number (6.0221415*10^23) of molecules. So 58 moles is equal to
58 * (6.0221415*10^23) = 3.49284207 *10^25 molecules