Question

Consider an ice cube with a volume of 0.50 cup. (1 cup = 240.0 mL, density of ice = 0.9167 g/mL). How many water molecules (molar mass = 18.015 g/mol) are present in this ice cube?

Answer 1

Answer:

3.86x10^24 molecules

Explanation:

From the question given, the following data were obtained:

Volume of ice = 0.5cup

1 cup = 240mL

0.5cup = 0.5 x 240 = 120mL

Density of ice = 0.9167 g/mL

molar mass of water = 18.015g/mol

First let us calculate the mass of ice. This is illustrated below:

Density = Mass /volume

Mass = Density x volume

Mass = 0.9167 x 120

Mass of ice = 110.004g = Mass of water

From Avogadro's hypothesis, we understood that 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole of water will also contain 6.02x10^23 molecules.

1mole of water = 18.015g

If 1 mole (18.015g) contains 6.02x10^23 molecules,

Therefore, 110.004g of water will contain = (110.004x6.02x10^23)/18.015 = 3.86x10^24 molecules