Avogadro constant/number

In terms of moles, Avogadro s hypothesis can be stated The same volume is occupied by one mole of any gas at a given temperature and pressure. The number of molecules in one mole is known as the Avogadro number constant. ... 

In discussing the proton transfer (66), we saw that one of the neutral species could be a solvent molecule. We shall discuss that case below. Here we may notice that, when all four species are solute particles, the number of solute particles is unchanged by the reaction, or Aq = 0. In such a case AF° happens to be equal to the characteristic unit U multiplied by Avogadro s constant. 

The number of objects per mole, 6.0221 X 1023 mol-1, is called Avogadro s constant, NA, in honor of the nineteenth-century Italian scientist Amedeo Avo-gadro (Fig. E.3), who helped to establish the existence of atoms. Avogadro s constant is used to convert between the chemical amount (the number of moles) and the number of atoms, ions, or molecules in that amount ... 

Number of objects = amount in moles X number of objects per mole = amount in moles X Avogadro s constant... 

A note on good practice Avogadro s constant is a constant with units, not a pure number. You will often hear people referring to Avogadro s number-, they mean the pure number 6.0221 X 1023. 

The amounts of atoms, ions, or molecules in a sample are expressed in moles, and Avogadro s constant, NA, is used to convert between numbers of these particles and the numbers of moles. 

The molar masses of elements are determined by using mass spectrometry to measure the masses of the individual isotopes and their abundances. The mass per mole of atoms is the mass of an individual atom multiplied by Avogadro s constant (the number of atoms per mole) ... 

Use Avogadro s constant to convert between amount in moles and the number of atoms, molecules, or ions in a sample (Examples E.l and E.2). 

The total number of molecules, N, is the product of the amount, n, and Avogadro s constant, NA so the last equation becomes... 

Avogadro s constant The number of objects per mole of objects (Na = 6.022 14 X 102 mol ). Avogadro s number is the number of objects in one mole of objects (that is, the dimensionless number 6.022 14 XlO2 ). Avogadro s principle The volume of a sample of gas at a given temperature and pressure is proportional to the amount of gas molecules in the sample V n. axial bond A bond that is perpendicular to the molecular plane in a bipyramidal molecule, axial lone pair A lone pair lying on the axis of a bipyramidal molecule. 

Avogadro, A., F39, 144 Avogadro s constant, F39 Avogadro s number, F39 Avogadro s principle, 38,... 

In (3) N is Avogadro s constant, r the radius of a conducting sphere, Z the charge number, and e the elementary electric charge. 

From the transition-state theory the reaction rate is represented by Equation 3, where Nj is Avogadro number and h is Plank s constant ... 

N = Avogadro number h = Planck constant c = velocity of light... 

The number of elementary entities in 1 mol is an experimentally determined quantity, and is called the Avogadro constant L, which has the value 6.022 x 1023 mol-1. The Avogadro constant is also (incorrectly) called the Avogadro number . It is... 

Volume of the unit cell (VcM). This may be calculated from the unit cell constants by using the following formulae. From this the density (/>) of the compound may be obtained p = Mcc /FccM, where MceH is the mass of the matter in the unit cell, that is the sum of the masses of all the atoms contained. The mass of an individual atom is calculated in grams by the ratio of the atomic molar mass and the Avogadro number. 

In one of his experiments, Perrin [6] counted a total of 13,000 particles of gamboge and found average concentrations proportional to the numbers listed in Table 21.1 at the given heights (h) above the bottom of the vessel. The experiment was carried out at 298 K, and the density of the particles was 0.2067 kg dm greater than that of the water in which they were suspended. The mean radius of the particles was 2.12 x 10 m. Calculate Avogadro s constant from these data. 

Born equation Jphys chemJ An equation for determining the free energy of solvation of an ion in terms of the Avogadro number, the ionic valency, the ion s electronic charge, the dielectric constant of the electrolytic, and the ionic radius. born i kwa zhan J... 

This tells us that the energy, E, carried by a photon is related to its frequency. The relationship between energy and frequency is = hf, where h is Planck s constant and has the value 6-63 x 10" J s. Using this relationship, the energy is calculated in joules (J). In chemistry, energy values are normally expressed in units of kj mol. To convert from J to kj the number value must be divided by 1000. To obtain mol in units of kJ mol, the relationship changes to E = Lhf, where L is Avogadro s constant. L has the value 6-02 x 10 mol. ... 

When the energy is in units of kJ mol, this is the energy associated with one mole of photons. Avogadro s constant is the number of formula units in one mole of a substance and so the number of photons in one mole of photons is 6 02 x 10 photons. 

General gas constant, R Loschmidt (Avogadro) number, N (number of particles per mol)... 

In equation (3.3), AAis the Avogadro number, k is Boltzmann s constant, and T is the absolute temperature. 

---