So the volume of water in the Atlantic ocean is around 354,700,000 cubic km, which is 354, 700, 000, 000, 000 cubic dm. Each mole of water contains 602,300,000,000,000,000,000,000 molecules and has a volume of 0.018 cubic dm. The sum is therefore:

(602,300,000,000,000,000,000,000 / 0.018) x 354, 700, 000, 000, 000 =

11,800,000,000,000,000,000,000,000,000,000,000,000,000
= 11.8 x 10^39 water molecules (give or take a few)!

Correction: The answer from Frank is a bit on the small side. A million times too small in fact, because there are a trillion litres in a cubic km, rather than a million as used in the answer.

It should say ‘There are 354, 700, 000, 000, 000, 000, 000 cubic decimetres of water in the Atlantic Ocean’.

This gives the correct figure of 11,800,000,000,000,000,000,000,000,000,000,000,000,000,000,000= 11.8 x 10^45 water molecules (six more zeroes than before) in the Atlantic Ocean.

That’s a lot of water.

Our thanks to Michael Grunwell for the correction.

## Comments

modantonycommented on :Correction: The answer from Frank is a bit on the small side. A million times too small in fact, because there are a trillion litres in a cubic km, rather than a million as used in the answer.

It should say ‘There are 354, 700, 000, 000, 000, 000, 000 cubic decimetres of water in the Atlantic Ocean’.

This gives the correct figure of 11,800,000,000,000,000,000,000,000,000,000,000,000,000,000,000= 11.8 x 10^45 water molecules (six more zeroes than before) in the Atlantic Ocean.

That’s a lot of water.

Our thanks to Michael Grunwell for the correction.