How many drops of water are in the ocean?

The ocean covers a lot as all of the named oceans and many of the seas are connected. So 'the ocean' is much bigger than 'an ocean', such as the Pacific Ocean. But if you mean the Pacific Ocean (the largest ocean of Earth) according to Wikipedia, the Pacific Ocean consists of "622 million cubic km of water". (Accessed 8/17/12)

There are about 20 drops of water in 1 milliliter(mL). For room temperature, pure water at atmospheric pressure, this is reliable to 20 drops = 1.00 mL, so our precision is about 1/100, about the same as Wikipedia's estimate of the volume. A mL is a centimeter cubed (cm3). There are 100 cm in 1 meter and 1000 m in a km, so there are 105 cm/km. Cube this term and you get 1015 cm3/km3. So multiply 20 drops/cm3 x 1015 cm3/km3 x 622 x 106 km3 = 12440 1021 drops. The second '4' and the trailing '0' of 12440 are a guess because we are only estimating, so putting it together we get, 1.24 x 1025 drops of water in just the Pacific Ocean.

You may have never heard of Avogadro's Number, 6.022 x 1023, but an Avogadro's Number of something is said to be a mole of something. For example, a mole of carbon-12 atoms has a mass of 12 g (definition). The number of drops of water in the Pacific Ocean is about 20.7 moles. If we matched one atom of carbon for every drop of water in the Pacific Ocean, the carbon would weigh only 248 g or about 8.75 ounces of carbon.