One mole of something, this is for chemistry? I don't understand !?

Answer 1

For example.

H2O is 1 molecule or 1 mole of water. So, 2H2O is 2 moles of water.

H2O is 2 atoms of Hydrogen + 1 atom of Oxygen and has a molecular mass of: - Hydrogen 2 x 1 = 2 + Oxygen = 1 x 16
Mol.Mass = 2 + 16 = 18
So, besides H2O being 1 mole of H2O it can also equal 18gram/mole. (18g/mol).
This can now be used to find the % Hydrogen and Oxygen in the molecule.
H2 = 2. Divide this by the 18 (mol.mass of H2O)
to give 2/18 = 0.111 and as a %, multiply by 100 = 11.1% Hydrogen.
This means that the Oxygen must be 88.9%.

(To check this. 16/18 = 0.889 = 88.9% Oxygen)

Answer 2

A mole is like a dozen, a pair, or a score... it means a certain number of things. Like a pair is 2, a dozen is 12, and a score is 20.

OK, so a mole is 602,000,000,000,000,000,000,000 or that is, a 6 followed by 23 zeros, written as 6 x 10^23.

You could have a mole of candy bars, a mole of chickens or a mole of anything you want, except that a mole of anything large enough to see would make a heck of a big pile! A mole of chickens would be a pile way larger than the whole earth.

We use moles to count atoms or other small particles because there are a lot of those things. Its a lot easier to say "1 mole" than to say 6 followed by 23 zeros.

The reason why we call this avogadros number is because a very smart amateur chemist in Italy started figuring out how atoms worked. He didnt actually figure out the number himself, but after he died people used some suggestions he had made and they were able to figure it out.

Moles are very useful because the way we have set things up in chemistry, using moles makes it easy to measure and calculate amounts of atoms. If you take a mole of atoms of an element, that many atoms turns out to weigh the same number of grams as the atomic weight of the element. This is really useful. Say I want to combine 2 atoms of hydrogen for every atom of oxygen. A mole of hydrogen atoms weighs one gram. So two grams of hydrogen is 2 moles. And a mole of oxygen is 16 grams. All I have to do is weigh the stuff and I can know exactly how many atoms there are. When the hydrogen and oxygen are combined, I will have a mole of water molecules H2O. This is no more complicated than saying that if I had a mole of bread and another mole of bread and a mole of salami, I could make a mole of salami sandwiches.

Another useful thing that was discovered is, if you have exactly one mole of gas particles - that is, either atoms or pairs of atoms or molecules - then that amount of atoms will take up 22.4 liters of space at standard temperature and pressure. That makes it easy to count the atoms in a gas.

There is no simple way to learn chemistry. It is a hard subject. So if you want to learn it, if you need it to be a premed student or for nursing or science, then you just have to work and work at it until you get it. Do every problem in the book until you get it. In the end you will have a WAY better understanding of how stuff in the world operates.

Answer 3

A mole is the unit for amount. Because there are so many atoms instead of counting in 1s, which would take forever, we count in moles.
The number of things in a mole is a very big number called, Avogadro's number, 6.022×10^23 things per mol

Answer 4

The mole measures an amount of substance. One mole contains Avogadro's number (approximately 6.022×10^23) entities. A mole is much more like "a dozen" in that both units can describe any set of elementary objects, although the mole's use is usually limited to measurement of subatomic, atomic, and molecular structures. This is all due to the fact that a mole represents an exceedingly large number of entities.

Answer 5

A mole is a chemical mass unit defined to be 6.022 x 1023 molecules, atoms, or some other eensy weensy unit. The mass of a mole is the gram formula mass of a substance.

Answer 6

I MOLE OF ANY SUBSTANCE HAS 3 MEANINGS:
1.ACCORDING TO AVOGADRO'S NO. 1 MOLE=6.023*10 TO THE POWER 23 MOLECULES.
2.ACCORDING TO VOLUME.22.4LITRES=1 MOLE.
3.ACCORDING TO R.M.M. RELATIVE MOLECULAR MASS. GIVEN MASS=1 MOLE=6.023*10 TO 23 MPLECULES.
I STUDIED THIS CHAPTER YESTERDAY.

Answer 7

One mole of a substance is equal to it's molecular weight.

Answer 8

a mol = 6*10^23

Answer 9

a mole is a unit of concentration, i.e. weight per volume. 1 mole of hydrogen would be 1.0g/mL 1 mole of oxygen would be 16g/mL