Final answer:
There are approximately 9.033 x 10^23 water molecules in 27 grams of water. This is calculated by first converting grams to moles using the molar mass of water and then multiplying the moles by Avogadro's number.
Step-by-step explanation:
To find the number of molecules in 27 grams of water, we need to follow a few steps using the molar mass of water and Avogadro's number. First, we use the molar mass of water, which is 18.015 g/mol, to convert grams to moles. The molar mass acts as a conversion factor between mass and moles:
27 grams x (1 mol / 18.015 grams) = 1.5 mol
Now that we have the number of moles, we can use Avogadro's number, which is 6.022 x 1023 molecules/mol, to find the number of molecules:
1.5 mol x (6.022 x 1023 molecules/mol) = 9.033 x 1023 molecules
So, there are approximately 9.033 x 1023 water molecules in 27 grams of water.