Calculate the mass of the following?

Question

3.01 x 10^23 molecules of water.

Answer 1

First find the moles of water. One mole is Na = 6.02x10^23 molecules, so:

n = N/Na = 3.01x10^23/6.02x10^23 = 0.5 mol

The relative molar mass of H2O equals Mr = 18, so:

m = n*Mr = 0.5*18 = 9 g

Answer 2

6.02 x 10^23 molecules of water is 1 mole or 18 gram of water (by definition).

so 3.01 x 10^23 molecules of water is 0.5 moles or 9 gram of water.

Answer 3

multiply the number of moleucules by the amu of water, H2O

Answer 4

27g