Question

The spherical volume of a H2O molecule is 0.00818 nm3 (in reality, this is a very close approximation of the volume of a H2O molecule). How long a "chain" would a 0.65 of a mole of water molecules be?

Answer 1

For a sphere,

solving for r, we get

radius of the water molecule, r = 0.125 nm

1 mole water = 6.022 x 10²³ water molecules

Number of water molecules in 0.65 mole of water = (0.65)(6.022 x 10²³) = 3.914 x 10²³ molecules.

Hence, length of the chain of 0.65 mole of water molecules

= (radius of each molecule) x (number of molecules)

= (0.125 nm)(3.914 x 10²³) = 4.89 x 10²² nm = 4.89 x 10¹⁰ km    (1 nm = 10^-9 m = 10^-12 km)

Therefore, the chain would be 4.89 x 10¹⁰ km.