- 3163 - AVOGADRO’S - number of molecules in a Mole? This review answers the question, Are there as many oxygen atoms in a single breath as there are breaths in all the Earth’s atmosphere? What’s your guess, “i.e. calculation“
- ---------------- 3163 - AVOGADRO’S - number of molecules in a Mole?
- There are as many oxygen atoms in a single breath as there are breaths in all of Earth’s atmosphere.
-
- How can you possible prove this? Show me the math.
-
- Amedeo Avogadro came up with a theory and a number that has the answer. Avogadro (1776 - 1856) was born in Turin, Italy. He was a lawyer in a family of lawyers, but, Avogadro turned to science as his later career. He wrote this theory in 1811 when he was 35 years old. Equal volumes of gas under equal conditions of pressure and temperature contain an equal number of molecules.
-
- Avogadro actually coined the word “molecule” He surmised that the gas was not individual atoms but probably combinations of atoms. The number of molecules in one mole of gas is 602,200,000,000,000,000,000,000 molecules.
-
-------------- Avogrado’s Number = 6.022*10^23 molecules
-
- A mole of a particular gas is defined as the mass in grams equal to the atomic weight of that gas. Oxygen has an atomic weight of 16. Since Oxygen gas is a molecule of two oxygen atoms. One mole of Oxygen gas is 32 grams.
-
- 32 grams of oxygen gas occupies 22.4 liters of volume at atmospheric pressure and 0 C and has Avogrado’s Number, 6.022*10^23 molecules. Since Oxygen molecule has 2 atoms, 32 grams has 12.044 * 10^23 atoms. Or, one gram contains 0.376*10^23 atoms.
-
- The average capacity of your lungs is 6 liters. But, normal breathing only uses a fraction of lung capacity, say 1 liter per breath. A liter of air weighs 1.2 grams. The amount of oxygen in the atmosphere is 20.95%. A normal breath only uses 5% of what it takes in and exhales 95% of the oxygen. Therefore a normal breath takes in 1.2*20%, or 0.25 grams of oxygen.
-
------------- Avogrado’s Number = 6.022*10^23 molecules / 32 grams
-
- One gram contains 0.376*10^23 atoms, and, one breath contains 0.25 grams of oxygen.
-
----------------------- 0.25 grams / breath * 0.376 *10^23 atoms / gram =
-
----------------------- 0.094 * 10^23 atoms per breath.
-
- The Earth’s atmosphere weighs 5*10^21 grams. Divide by 0.25 grams / breath and the Earth’s atmosphere contains 20,000,000,000,000,000,000,000 breaths of air, or, 20*10^21 breaths.
-
- 20 * 10^21 breaths is about the same as 9.4 atoms of oxygen, especially if you take a little deeper breath.
-
- Avogadro came up with his theory realizing that the amount of material in a gas cylinder depending on volume, pressure and temperature. Holding Temperature constant the Volume is proportional to 1/Pressure.
- Whenever we say one variable is proportional to another variable you can change the expression into an equality by finding the appropriate “ Constant of Proportionality”
-
-------------- x is proportional to y
-
-------------- x = k * Y
-
--------------- where: k = the Constant of Proportionality.
-
- Pressure * Volume = Avogadro’s Number * Constant Proportionality * Temperature
-
---------------- P*V = N*K*T
-
- In this case “K” is the Universal Gas Constant “K” = 8.314 joules / mole* Kelvin
-
- Instead of using moles we can use Avogadro’s Number of molecules per mole
-
---------------- P*V = N*k*T
-
- In this case, “k” is Boltzman’s Constant. “k” = 1.381*10^-23 joules / Kelvin
- Actually Avogadro’s Number not only applies to gases, it works for a mole of any substance, liquid or solid. You can use Avogadro’s Number to calculate the masses of all the elements in the Periodic Table.
-
---------- Oxygen 32 grams / mole * mole / 6.023*10^23 atoms = 5.3*10^-23 grams per molecule, or 2.5 *10^-23 grams per atom.
-
- You can use Avogadro’s Number to calculate the diameter of an atom. The diameters of atoms is about 10^-10 meters.
-
-------------------------------- See Review 101 “ Who is Ludwig Boltzman?
-
-------------------------------- Another review about Avogadro:
-
- 2987 - AVOGADRO’S - kilogram has how many moles? To measure the mass in kilograms we need to have a kilogram standard. Science would like to have a standard defined in some way tied to nature’s fundamental constants. Like the length of the meter is defined in terms of the constant speed of light.
-
- Avogadro Constant is defined as the number of molecules contained in a “mole” of any substance. The Constant is a proportionality factor and is the same for all substances, 6.022*10^23 per mole.
-
- Mole, that has the symbol “mol”, is an amount of substance that contains as many elementary entities as there are atoms in 0.012 kilograms of carbon-12.
-
- In other words, the number of atoms in the atomic weight of carbon-12 measured in grams. The elementary entities must be specified as atoms, molecules, ions, electrons, or other particles.
-
- There is always confusion between atoms and molecules, atomic weights and molecular weights, but, Avogadro’s Number of Proportionality works for either.
-
- May 18, 2021 AVOGADRO’S - molecules in a Mole? 1072 3163
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
--------------------- --- Tuesday, May 18, 2021 ---------------------------
No comments:
Post a Comment