How many hydrogen atoms are in a 27.0 g sample of water (H₂O)?

Question

Quizplus · Accepted Answer

First we need to determine the number of moles of water in the sample:
27.0 g H2O / 18.015 g/mol H2O = 1.499 mol H2O
Each molecule of water contains 2 hydrogen atoms, so:
1.499 mol H2O x 2 mol H / 1 mol H2O = 2.998 mol H
Finally, we need to convert moles of hydrogen atoms to actual number of atoms, using Avogadro's constant:
2.998 mol H x 6.022 x 10^23 atoms/mol = 1.81 x 10^24 atoms
Therefore, the answer is D) 1.81 x 10^24.

How Many Hydrogen Atoms Are in a 27