27g of H2O, how many hydrogen atoms?

Question

Hey I did this myself but can't get it right.
a) what i did was find the molar mass of H2 in 27g h2O, 2g/27g= .074mol H2

b) i then converted .074mol to # of atoms by multiplying this by Avogadros #, .074 x 6.02e23= 4.54atoms H2 in 27g sample of H2O.

*However according to my homework the write answer is supposed to be 1.81 x 10e24

Answer 1

Lets try it this way:
27 g of H20= 27/18= 1.5 mol of water = 3 mol of H atoms
3 mol of H atoms= 3 * avagodro's number
= 3 * 6.02e23
= 18.06e23
= 1.806e24
Which as you have pointed out is the answer!!
All the best.

Answer 2

i don't be attentive to the type you won 3 or 4 hydrogen atoms... yet it incredibly is how I set it up: (38.57 mol HC(2)H(3)O(2)) x (4mol H/ a million mol HC(2)H(3)O(2)) x (6.022 x 10^23 atoms of H/ a million mol H) = 9.2907 x 10^25 atoms H In sigfigs this is: 9.291 x 10^25 atoms H want I helped.

Answer 3

it should be done like this

18g of h2o has 2 atoms of h2
then 27g of h2o has how many atoms

the answer is 3 atoms
then multiply it with the avogadro no. then you get the answer you have there

Answer 4

One mole of water weighs 18 grams; 27 grams of water contains 1.5 moles. There are two atoms of hydrogen in every mole so there are 3 moles of hydrogen. Each mole has 6.023 x 10^23 atoms of hydrogen so 3 x 6.023 x 10^23 = 18.069 x 10^23 atoms hydrogen or

1.8069 x 10^24 atoms, Answer