Question

Please Help :-
Explain the Mole Concept.
( in deep sense )

Answer 1

mole = mass in gms /molar mass

Answer 2

Depends on how deep you want to go... A mol is a unit used to measure a discrete and utterly insanely tremendous number of particles, such as individual atoms or molecules. About 6.022E23 particles in fact.

Answer 3

Are you wondering how that number was decided upon maybe?

Answer 4

i wan't it in much deeper sens... plz help me out

Answer 5

A mole is 6.02214179×10^23 molecules/atoms. So it's like saying I have a dozen molecules of this substance, but instead of a dozen which is 12, a mole which is that number I said before (which btw it's called Avogadros number). The molar mass is the mass of a mole of molecules of that substance. Therefore, if you wanna know how many moles of this substance I have you divide the mass by the mass per mole, that is the mass by the molar mass.

Answer 6

1 mole = 6.02 *10^23 particles

Answer 7

Originally 1 mol was used to represent 1 g of hydrogen, but there's two issues with that:
1. Hydrogen is a gas, meaning it has indefinite volume (and volume is needed when calculating density) that varies based on pressure and temperature. A solid would be much preferred. (good luck getting solid hydrogen though lol)
2. The idea of a mol was proposed before the mass of the electron was properly discovered and recorded.

So what did they use instead? Carbon. Solid, pure carbon. Specifically carbon that is only carbon-12 (not the radioactive carbon-14 isotope).

Guess what one mole of pure C\(^{12}_6\) weights? EXACTLY 12 grams. This is the official definition.



The reason the atomic weights you see on the periodic table are not nice, whole integer numbers is because you're averaging the molecular weights against the other isotopes. Carbon reads as 12.01 grams per 1 mole on the periodic table because (except for ancient fossils & rocks) there's a little bit of radiation out in our environment (mostly from the sun) and that radiation create isotopes (carbon that has picked up extra neutrons). These isotopes will change the averages. Some elements don't even have a "stable" non-radioactive isotope, such as Plutonium or Technetium.

Answer 8

well i understood it by example of ping-pong balls and the tennis balls
if u take equal number of tennis balls and ping-pong balls say 100 each
then
mass of one tennis ball= mt (say) and mass of one ping-pong ball=mp (say)
then total mass of tennis ball / total mass of ping-pong ball = mt X 100 /mp x 100 =mt/mp

that is if we take the masses of two substances in the ratio of their respective atomic weight or molecular wieght they will contain the same number of atoms or molecules
that is i mole of H atom = 6.022x 10 to the power 23 H atoms = 1.008 gm

Answer 9

\[\frac{1 \text{mol Carbon}}{602,214,150,000,000,000,000,000 \ \text{atoms of Carbon}}\]

or

\[\frac{602,214,150,000,000,000,000,000 \ \text{atoms of Carbon}}{1 \text{mol Carbon}}\]

We write this insanely large number as 6.0221415*10^23 or ~6.022E23

Answer 10

@agentx5 and @kritima
Plz explain me Equivalent weight also

Answer 11

You can convert by the way with that. If I tell you how many particles you have then you can tell me the # of moles, or in reverse, # of moles to # of particles.

And I just explained where equivalent weight historically comes from above, did you read?

Answer 12

For molecules the equivalent weight (aka. atomic mass units, or "amu" for short) is simply the sum of the atomic weights off the periodic table. Those atomic weights take into account the AVERAGED weight of the "normal"/"stable" isotope, and the radioactive ones found in small percentages in nature.

Isolating isotopes by the way is extremely complex, using special centrifuges that are well-kept secrets of the nations in the world that have atomic weaponry. Nations that don't, frequently keep on trying to get there (i.e. Iran) and what's slowing them is how technologically complex it is to get enough U-235 separated from U-238 and/or manually creating Plutonium (not to mention Australia, Kazakhstan, and Canada have the only reliable concentration of pitchblende ore, where you get this extremely rare metal). So yeah, most of the material for the world nuclear arsenal or nuclear reactors was originally dug up in Canada or Australia.

Answer 13

equivalent weight of an element is the number of parts by weight of that element which combine with or displace directly or indirectly 1.008 parts by weight of hydrogen or 8 parts by weight of oxygen or 35.5 parts by weight of chlorine or it's equivalent

for example consider a reaction between magnesium and sulphuric acid
Mg +H2SO4 = MgSO4+H2
here 2 parts by wt. of H2 are displaced by 24 parts by wt. of Mg
then
1 parts by wt. of H2 are displaced by 12 parts by wt. of Mg
then equivalent wt of Mg is 12