How many molecules are there in 57.9 moles of H2O

3.49x 10^25 molecules H2O

Explanation: To find the number of molecules of H2O we will use the relationship between moles and Avogadro's Number.

57.9 moles H2O x 6.022x10²³ moles H2O / 1 mole H2O

= 3.49x10^25 molecules H2O

Cancel out the moles of H2O.

57.9 moles of H2O contains 3.48 × 10^25 molecules

Explanation:

⇒ 57.9 × 6.022 x 10^23 = 348.67 × 10^23

                                        = 3.48 × 10^25 molecules