Question

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)

Answer 1

The beaker contains approximately 2.346 x 10^24 molecules of water

Step-by-step explanation:

The number of molecules of water in a 70 ml beaker can be calculated by using the concept of Avogadro's number. Avogadro's number is a constant that represents the number of atoms or molecules in one mole of a substance, and it is approximately equal to 6.022 x 10^23.

1. First, we need to determine the mass of water in the beaker. Since the density of water is 1.0 g/ml, the mass of 70 ml of water is 70 grams.
2. Next, we need to convert the mass of water to moles by dividing it by the molar mass of water, which is approximately 18 g/mol.
3. Finally, we multiply the number of moles by Avogadro's number to find the number of molecules. Therefore, the beaker contains approximately 2.346 x 10^24 molecules of water.

Answer 2

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