3. How many molecules are in 2.10 moles of H2O?

Explanation:

The number of molecules can be found by using the formula

N = n × L

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

N = 2.10 × 6.02 × 10²³

We have the final answer as

Hope this helps you

fe 55.85 g/mol and h2o 18.02 g/mol.