How many molecules of water are there in the ocean..?

…I make it 4.5166×10(47), but then again, I could be wrong 😉

42

Which ocean?

Ohh, get you Drac 8)

Drac – Moderator
Which ocean?

Well Captain is right but only the Pacific the Alantic has 49 I think.

there’s a lung-full less since 2004, I remember drinking a bit of the med

The Mediterranean Ocean?

How did you work it out?

Find out how many litres of water to get the mass of water. If you don’t have that then you’ll want the average depth of the oceans x their area x density of 1 (and a bit if you are picky). Then divide by the weight of a mol to get the number of mols then x 6×10^23 aka Avagadro constant. Blam.

there’s a lung-full less since 2004, I remember drinking a bit of the med

So where’d that water end up? 🙂

it’s in a jar on my mantlepiece

Lots?

there’s a lung-full less since 2004, I remember drinking a bit of the med

It’s okay I pissed a similar amount back in in 2006 😀

i’ve just run the tap in the kitchen for a bit, knowing full well it’ll end up in the ocean and screw up your results 😈

(serious point here… seeing as water moves about the planet in various forms… wouldn’t the volume of clouds at any given point, amount of freshwater etc etc etc all influence any results?)

Yes but not by much. There is a LOT of water in the sea.

molgrips – as you go deeper and the water is more compressed does that not mean there are more molecules per litre?

water is quite hard to compress

The pressure is higher, it hasn’t compressed tho.

there’s a lung-full less since 2004, I remember drinking a bit of the med

It’s okay I pissed a similar amount back in in 2006

I’m sure a few ice shelves have fallen into the south atlantic since then and added a few more cup fulls.

Kev

“The mass of the oceans is approximately 1.35×10(18) metric tons” …from a famous online possibly spurious (?) encyclopedia information source.

1.35×10(18)tonnes = 1.35×10(24)grams

1 mole of H2O = 18grams

1.35×10(24) / 18 = 750×10(22)moles of water

750×10(22) x Avagadro’s constant = 4.5166×10(47)

…I think?

0 – Water is not a molecule.

Water is not a molecule.

It was when I did my chemistry degree, what’s changed since then?

If you’re doing this as some kind of assignment you’ll get marked down for using too many significant figures in your calculation. Or at least you should do.

too many significant figures

I know that STW people are important but…

0 – Water is not a molecule.

Chemistry FAIL

Surely, technically, he is correct: water is not a molecule, water is a collection of H20 molecules, plus all sorts of other impurities.

If you had one H20 molecule in the palm of your hand, could you realistically call it water?

If you had one H20 molecule in the palm of your hand, could you realistically call it water?

Yes.

A grain of sand is still sand. It’s not cheese.

Anyway that has to be the most ridiculous attempt at pedantry I’ve seen!

Incorrect: One grain of sand is silica, sand is the collective term for the granular material it is a constituent of.

I’m not saying he is right in his pedantryness, I’m just pointing out that you shouldn’t dismiss the comment out of hand.

Incorrect: One grain of sand is silica, sand is the collective term for the granular material it is a constituent of.

Not sure I agree there. Sand is scilica, a grain of sand is scilica. Sand is not a colletive noun.

Surely a grain of sand IS sand, but once it’s smaller than a grain it ceases to become sand and then becomes whatever silica is referred to when it’s smaller than a sand grain size?!!

(I’m learning new levels of pedantry at STW!)

Having said that, colloquial references to “water molecules” exist and are referred to on a regular basis. So on tha aspect I reckon you can describe an H2O molecule as water.

there is indeed a lot of water on our planet.

think of a really big number, and it’s probably more than that.

97% of it is saltwater.

2% is ice.

1% is fresh water – that includes all the lakes, rivers, clouds, water in apples, people, bottles of beer, etc.

i has a ‘national geographic’ on my desk: ‘water – our thirsty world’

it’s ace.

it says that we’ve got 366 million million million million gallons, but doesn’t say if that’s uk or US gallons…

water is not a molecule

but a water molecule is…

If you had one H20 molecule in the palm of your hand

whaddya mean “if” ? Most of your whole frikken hand IS water!

Surely a grain of sand IS sand, but once it’s smaller than a grain it ceases to become sand and then becomes whatever silica is referred to when it’s smaller than a sand grain size?!!

Sand grains can be as small as you like.

Look – sand is a number of sand grains. One is a number. So one sand grain is still sand!

One grape is not a bunch of grapes, because in this case BUNCH is a collective noun, and you can’t have a collective of more than one.

Likewise a crowd can’t be one person because a crowd specifically means lots of people.

there is indeed a lot of water on our planet

I would expect there’s very much more IN our planet.

all this talk of water and sand makes me want to go to the beach.

Kev

as in “Two’s company, three’s a crowd” ? Or is that still not enough ? Interesting that we have several imprecise numbers:
a couple, 2 or 3 and definitely not less, but probably not more
a few, at least 3 (?) but less than what, 10 ?
lots, at least 5 ?

Th properties of water are discerned by the interaction between the composite molecules of H20. One single molecule of H20 does not exhibit the same properties as water.

Sand grains can be as small as you like.

Really? I was under the impression that sand became progressively finer until it became silt, then eventually clay. Whereas the other end of the spectrum it becomes larger and turns into grit, then maybe gravel.

Any geologists on STW confirm this?

sand is a number of sand grains. One is a number. So one sand grain is still sand!

Sand is made up mostly of silica in the form of quartz with a general formula SiO2 as it forms in a tetrahedral arrangement whereby the oxygens are shared between 2 tetrahedra with a silicon atom in the middle. Therefore if you only have 1 silicon atom, and 2 oxygen atoms to make one SiO2 molecule you can’t make quartz, and therefore you can’t make sand.

would it be easier to swim if all water was carbonated?

Th properties of water are discerned by the interaction between the composite molecules of H20. One single molecule of H20 does not exhibit the same properties as water.

Err no, some of the properties of water are defined by its interaction but not all of them are e.g. molecular weight, bond angles, that sort of thing.

Oh and of course water is a molecule.

Edit:

would it be easier to swim if all water was carbonated?

No, you’d be less bouyant and likely drown.

would it be easier to swim if all water was carbonated?

I think it would be harder as the water would be less dense and you’d be more likely to sink