Answer:
The number of molecules in 895 g of H₂O is 4.49*10²⁵.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression. Avogadro's number applies to any substance.
In this case, the molar mass of compound H₂O is 18 g / mol. So if 18 grams of H₂O are present in 1 mole, 895 grams will be present in how many moles of H₂O?
[tex]moles of H_{2}O=\frac{895 grams*1 mole }{18 grams}[/tex]
moles of H₂O= 74.58
Then the following rule of three can be applied: if 1 mole of the compound contains 6.023 * 10²³ molecules by definition of Avogadro's number, 74.58 moles of the compound how many molecules will it contain?
[tex]amount of molecules=\frac{74.58 moles*6.023*10^{23}molecules }{1 mole}[/tex]
amount of molecules=4.49*10²⁵
The number of molecules in 895 g of H₂O is 4.49*10²⁵.
