Answer:
there are approximately 5.5 x 10^23 molecules in 16.5 grams of water
Step-by-step explanation:
To calculate the number of molecules in a certain mass of a substance, you need to know the molar mass of the substance and convert the mass to moles.
The molar mass of water is 18.015 g/mol. To convert the mass of water to moles, we can use the equation:
moles = mass / molar mass
So, moles of water = 16.5 g / 18.015 g/mol = 0.916 mol
Avogadro's number is 6.022x10^23. To calculate the number of molecules, we can multiply Avogadro's number by the number of moles.
So the number of molecules = (6.022x10^23) * (0.916 mol) = 5.5x10^23 molecules
Therefore, there are approximately 5.5 x 10^23 molecules in 16.5 grams of water