Question

What would be the mass of 1.98x10^28 molecules oh H2O

Answer 1

whoa! Do you ever do a sanity check on your answer?
Molar mass of H2O = 18.015 g/mol
That means that we have (1.98x10^28)/(6.023*10^23) * 18.015 = 5.92 x 10^5 g

Answer 2

To find the mass of 1.98x10^28 molecules of H2O, we first need to calculate the molar mass of H2O.

H2O has a molar mass of 18.015 g/mol (2(1.008 g/mol) + 15.999 g/mol).

Now, we can calculate the mass of 1.98x10^28 molecules of H2O:

Number of molecules = 1.98x10^28 molecules
Molar mass of H2O = 18.015 g/mol

Mass = Number of molecules x Molar mass
Mass = 1.98x10^28 molecules x 18.015 g/mol
Mass = 3.57x10^29 g

Therefore, the mass of 1.98x10^28 molecules of H2O is 3.57x10^29 grams.

Answer 3

I apologize for the mistake in my previous response. Thank you for catching that error and providing the correct answer with the correct sanity check.

The mass of 1.98x10^28 molecules of H2O is indeed 5.92x10^5 grams. Thank you for the correction.