Science Mole Paper 4d4z2o

Aman Panjwani Chemistry Pre-AP F 11/22/13

Research Questions 1. Amedeo Avogadro was born 9th August 1776 to a wealthy family in Piedmont, Italy. At the age of twenty-one he graduated with a degree in ecclesiastical law, the study of the laws governing the Catholic Church, and began to practice soon afterwards. Not long after, Avogadro dedicated himself to the studies of physics and mathematics and in 1809 he started teaching them at a high school in Vercelli. In 1820, Amedeo became a professor of physics at the University of Turin and a year later he was very active in the revolutionary movements against King Victor Emmanuel I. Consequently, he lost his chair in the university in 1823. Over Avogadro’s life he had six children and a wife named Felicita Mazze. After living and contributing for 79 years, Amedeo Avogadro died 9th July 1856. Amedeo Avogadro’s contributions to society started when he was thirty-four and published an article titled Essay on Determining the Relative Masses of the Elementary Molecules of Bodies and the Proportions by Which They Enter These Combinations. This publication contained Avogadro’s hypothesis, also known as Avogadro’s Law, which stated the relationship between the masses of the same volume of different gases corresponded to the relationship between their molecular weights. Avogadro developed his hypothesis after Joseph Louis Gay-Lussac published his law on volumes and combining gases in 1808. The problem Amedeo had to resolve was the confusion behind atoms and molecules. One of his greatest accomplishments was distinguishing atoms and molecules such that gases were said to be composed of molecules and molecules composed of atoms.

After Avogadro’s death, his work and contributions was thoroughly criticized and did not receive attention. Three years after his death another scientist by the name of Andre Marie Ampere achieved the same results but his work was shown indifference also. Only after the studies of Charles Frederic Gerhardt and Auguste Laurent was Avogadro’s law explained and accepted. In 1911, a meeting in Turin celebrated the hundredth anniversary of the publication of Avogadro’s 1811 paper. This meeting was attended by the King of Italy thus Avogadro’s contribution to chemistry was finally recognized. In the end, Avogadro’s contributions to molecular theory resulted in the honor of having the number of molecules in one mole be named Avogadro’s number and he was hailed as the founder of the atomic-molecular theory.

2. Johann Josep Loschmidt was the first to propose the number of 6.022 x 10^23 to describe the number of particles in one mole of a substance. In 1865, Loschmidt estimated the average diameter of a molecule in air using a method that was equivalent to calculating the number of particles in a given volume of gas. The number of particles in a volume of gas is called the Loschmidt constant and is the number density, or

is related to Avogadro’s number, or NA, by

or particles, in an ideal gas. This constant

. In

the previous equation, p0 is the

pressure, R is the gas constant and T0 is the absolute temperature. Using this equation, Johann was able to estimate the value of 6.022 x 10^23 using his new discoveries and previous knowledge.

3. A. Molar Mass- the mass in grams of 1 mol of a substance B. Molarity- a concentration unit of a solution expressed as moles of solute dissolved per liter of solution C. Molality- the concentration of a solution expressed in moles of solute per kilogram of solvent D. Avogadro’s Law- the law that states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules E. Charles’s Law- the law that states that for a fixed amount of gas at a constant pressure, the volume of the gas increases as the temperature of the gas increases and the volume of the gas decreases as the temperature of the gas decreases F. Gay-Lussac’s Law- the law that states that the volume occupied by a gas at a constant pressure is directly proportional to the absolute temperature G. Boyle’s Law- the law that states that for a fixed amount of gas at a constant temperature, the volume of the gas increases as the pressure of the gas decreases and the volume of the gas creases as the pressure of the gas increases H. Dalton’s Law of Partial Pressure- the law that states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases I. Ideal Gas Law- the law that states the mathematical relationship of pressure (P), volume (V), temperature (T), the gas constant (R), and the number of moles of a gas (n); PV = nRT J. Molar Volume of Gases- the volume occupied by one mole of a gas at standard temperature and pressure, it is equal to 22.414 10 L

4. In chemistry, the mole is a unit of measure used to express amounts of a chemical substance and corresponds with the value of 6.022 x 10^23. Furthermore, in chemistry it is used as a convenient way to express amounts of reactants or products of chemical reactions. The number of molecules in a mole is defined in such a way that the mass of one mole of a substance is exactly equal to the substance’s molecular mass allowing chemists to simply chemical equations.

5. A mole ratio in a balanced chemical equation is a conversation factor that relates the amounts in moles of any two substances involved in a chemical reaction. It is used to covert from moles or grams of one substance in a reaction to moles or grams of another substance. These ratios are used in the broader concept of stoichiometry, which deals with either the mass relationship of elements in compounds or between reactants and products in a chemical reaction.