2007-02-28 01:30:02 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
weight of 6.023*10^23 molecules of water is 18g
weight of one molecule is=2.988*10^-23g
2007-02-28 01:46:56 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Yes, 18 is very, very close for the weight per mole.
However, for the weight per molecule let's get a bit more exact. . .
A hydrogen atom has an atomic weight of 1.00797
An Oxygen atoms has a weight of 15.9994
Water Molecule has an atomic weight of 18.01534
A mole of water (6.0225E23 molecules)= 18.01534 grams
One moldcule of water = 2.991339145E-23 grams
2007-02-28 09:49:36 · answer #2 · answered by Walking Man 6 · 0⤊ 0⤋
The mass of a molecule of water is given by the molar mass (18g/mol) divided by the avogardo's constant (the number of molecules of water in one mole of water)= 18/6.0221415 Ã 10^23= 2.98897 x 10^-23 g.
2007-02-28 09:39:13 · answer #3 · answered by The exclamation mark 6 · 0⤊ 0⤋
The weight of a molecule is determined by the atomic masses of the atoms that it is built of. The atomic mass of an atom is determined by the addition of the number of protons and neutrons in the nucleus, because the electrons hardly weigh anything.
When the atomic masses of the separate atoms are known, one simply has to add them up to find the total atomic mass of a molecule, expressed in grams per mol. A mol is an expression of the molair weight of a molecule, derived from the weight of a hydrogen molecule, which is 1 mol.
Hydrogen has a relative atomic mass of 1 g/ mol and oxygen has a relative atomic mass of 16 g/ mol. Water consists of one oxygen atom and two hydrogen atoms.
This means that the mass of a water molecule is 1g + 1g + 16g = 18 g/ mol.
When the number of moles of water is known, one can calculate how many grams of weight this is, by using the molar weight of water..
2007-02-28 09:35:11 · answer #4 · answered by Anonymous · 0⤊ 1⤋
a water molecule weighs 18g
2007-02-28 10:03:35 · answer #5 · answered by Arun 2 · 0⤊ 1⤋
THE WT OF THE WATER MOLECULE I.E THE I MOLE OF WATER .
THE WT. OF IMOLE =THE MOLECULAR WT.OF WATER.
=>H2O IS THE CHEMICAL FORMULA OF WATER
WHERE H2............>IS THE HYDROGEN MOLECULE
O.............>IS THE OXYGEN ATOM.
THUS THE MOLECULAR WT.OF WATER IS (16+2)a.m.u=18 a.m.u
a.m.u..........>ATOMIS MASS UNIT
2007-02-28 09:36:41 · answer #6 · answered by kartik 2 · 0⤊ 1⤋
18g
2007-02-28 09:38:03 · answer #7 · answered by Xiomy 6 · 0⤊ 0⤋