What is the mass (in grams) of one molecule of H2O? Express your answer using scientific notation with two decimal places.

Question

anonymous · Answer

do you know avagadro's number?

anonymous · Answer

yes

anonymous · Answer

ok do you know the mass number of H2O?

if we have a mole of molecules, the total mass is the value of the mass numbers in grams

ex. a mole of helium atoms would be 4g

so if we wanted to determine the mass of a single helium atom in grams, we could just divide 4g by avagadro's number

anonymous · Answer

mol of O- 16g
mol of 2H- 2g
mol of H20- 18g