General Knowledge - Chemistry - Discussion

Here mentioned room temperature and at STP the volume of a gas is 22.4L = 22400ml.
So, I think the correct answer is 4.83 * 10^16.

18ml of H2O = 6.023 * 10^23 molecules.
0.0018ml of H20 = 6.023 * 10^23 * 0.0018/18,
= 6.023 * 10^19.

It is because 1 mole of water is equal to the Avagadro number which is 6.023*10^19.

How do you get 18 out of .0018?

Please clear my doubt.

Good explanations. Thanks, everyone.

18 ml H2O.
no of molecule= 6.023x 10^19.
0.0018 ml of H2O.

No of molecule= (6.023x 10^19x0.00180/18= 6.023x10^19.

1mole H2O =18g =18ml = 6.023 * 10^23,
=>.0018ml =6.023 * 10^23 * 18/.0018,
=6.023 * 10^19.

1 mole of water contains an avagadro number(6.023*10^23) of molecules.1 mole of H2O mass is 18g or volume 18ml.

So 0.0018ml of water contains 6.o23*10^19 molecules.

1mol of H2O contains 6.023*10^23 molecules.

Here, mol=volume/atomic weight=0.0018/18 (h2o at weight =18) = 0.0001.
0.0001 mol H2O contains 6.023*10^23*0.0001 = 6.023 * 10^19 molecules.

Here One drop of water has the volume 0.0018 mL.
Because the density of water is 1, the mass is 0.0018 g. The molar mass of water (H2O) is 18.0 grams/mol (1.008 + 1.008 + 16.0). This means there is one mole of water in 18.0 grams. One mole is 6.02 x 1023 molecules.

Then you can convert grams to number of atoms:
0.0018 grams / 18.0 grams x (6.02 x 10exp19 molecules)

Read more: http://wiki.answers.com/Q/How_many_water_molecules_are_in_one_drop_of_water#ixzz1iphXiIJy