#1
This is for chemistry extra credit and i need to put one mole of water into a snowglobe
I know h2o has a molar mass of around 18g/mol but i forgot where to go from there
#4
go from mL to grams to mols. I think. You might have to do molarity. I can't remember. Maybe the 22.4 L / 1 mole thing.

I just learned this a few months ago
#5
Quote by freedoms_stain
I'm pretty sure with water 1g = 1ml.

ya thats what i thought. I think its 18 ml but im not sure
#6
Quote by RedDeath9
go from mL to grams to mols. I think. You might have to do molarity. I can't remember. Maybe the 22.4 L / 1 mole thing.

I just learned this a few months ago


Lol, that's for gasses at 25 degrees celsius.
#7
Quote by hendrixrocker2
This is for chemistry extra credit and i need to put one mole of water into a snowglobe
I know h2o has a molar mass of around 18g/mol but i forgot where to go from there


ur doing this mole **** too, eh?

I think its ****ing useless. who would ACTUALLY ****ING SIT THERE AND COUNT OVER 60200000000000000000000000000 ATOMS AND NAME IT A MOLE?!

Disgusting.
#8
H = 2(1)
O = 1(16)

#mol=(18ml*1mol)/18ml=1mol

I think.

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#9
EDIT: Nevermind
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#10
Water has a density of 1g/ml so 18 g is 18 ml problem solved

^That's not how moles work by the way, 1 mole of H2O is 1 mole of H20 not 2 moles of hydrogen and one of oxygen, there's 2 hydrogen atoms and 1 oxygen atom.
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#11
EDIT: Nevermind
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#12
Quote by The Picker
(1 mL H20) x (1 g/mL) x (18.02 mol/g) = 18.02 mol in 1 mL of H20

Do you know how to do molar masses? This would make it very much easier.


Wow just wow that was so wrong I won't even go into it

edit: Ok I won't be a dick about it, it's 18.02g/mol not 18.02mol/g
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#13
the answer is 18mL of water

1mol x 18g x 1mL = 18mL HOH
~1 ~~~1mol ~~1g


mol cancels with mol, grams with grams, leave it in mL
#14
He's asking about how many grams are in 1 mol of water!

Add the molar mass of Hydrogen*2 to the Molar mass of Oxygen.

1.001*2+16.00= 18.00 ml/mol
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#15
EDIT: Nevermind
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#16
actually 1 mol H20 has a mass of 18.02 g just in case your teacher is really specific.
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#18
Quote by lemon

That's not how moles work by the way, 1 mole of H2O is 1 mole of H20 not 2 moles of hydrogen and one of oxygen, there's 2 hydrogen atoms and 1 oxygen atom.



1 mol of H2O does in fact have 1 mol of oxygen atoms and 2 mol of hydrogen atoms.
#21
1ml of water is 1 g.

moles = mass/ Molar mass

molar mass = 18 g/mol -> (H = 1 (multiply it by two because theres two H atoms) O = 16)

moles = 1

rearrange to get: mass = Molar Mass * moles

substitute: mass = 18 * 1

Mass = 18 grams!
#23
Obviously a million. Millilitre. Million.

No, I didn't read the thread, and I skimmed TS's post.
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#24
Quote by lemon

^That's not how moles work by the way, 1 mole of H2O is 1 mole of H20 not 2 moles of hydrogen and one of oxygen, there's 2 hydrogen atoms and 1 oxygen atom.


Yes that IS how moles work.
1 mole is a fixed number, there is no definite weight to a mole.

People use moles to increase magnitude to make computations and experiments easier. So anything that applys in the atomic level is in theory directly related to anything in the molar level.

So if you want to yield one H2O molecule, you require two atoms of Hydrogen and one atom of Oxygen. However making one molecule is near impossible, so it's much easier to increase the volume and work with moles instead.

One O atom is 16.000 amu, and one H is 1.008 amu. So one molecule of H20 would be 18.016 amu.

Now because atomic mass and molar mass are similarly proportional, one mole of O is 16.000 g, and one mole of H is 1.008 g. This yields 18.016 g per mole.

So because atomic mass and molar mass are the same in terms of numbers, this also means that the proportions must be the same as well. That means that for one mole of H2O, in actuality you require 3 moles of reactant: 2 moles of H, 1 mole of O to create one mole of H2O
#26
Quote by CaptainRon
Actually its for gases at STP (Standard Temperature and Pressure) which is 273.15K and 101.325kPa.


At STP water would be frozen.
273.15 K is 0C, I'm pretty sure the 1g/1mL for water conversion was made at 4 degrees celcius. Don't quote me for that, I've also heard it true for 25C as well. But either way at a pressure of 1 atm, and a temperature where water doesn't evaporate or freeze the 1g/1mL conversion remains valid.

edit: This is true only for pure water.