A beaker contains 70 ml of water. how many molecules of water does this beaker contain? (hint: the density of water is 1.0 g/ml)

This part require data such as Avogadro's number and the molar mass of water. But first, let's find the mass of water in the specified volume by making use of the density formula:

Density = mass/volume

1 g/mL = Mass/70 mL

Mass = 70 g

Each water contains 18 grams per mole, and each mole contains 6.022*10²³ molecules of water. Thus,

70 g * 1mole/18 g * 6.022*10²³ molecules/mole = 2.342*10²⁴ molecules of water