Mole Day The Mole 6.02 x 1023 A very big number

Amadeo Avogadro Lorenzo Romano Amedeo Carlo Avogadro, conte di Quarequa e di Cerreto (1776 - 1856), was an Italian scientist noted to be one of the founders of physical chemistry. He was actually a physics professor but he experimented in both physics and chemistry using mathematics to base most of his findings.

6.0221367 x 1023 molecules Amadeo Avogadro Avogadro is well known for his hypothesis known as Avogadro's Law. His law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules regardless of their chemical nature and physical properties. 6.0221367 x 1023 molecules

How did the law become a number? Cannizarro (1860) used the Avogadro's hypothesis to develop a set of atomic weights based on 1/16 of the atomic weight of oxygen. This was the basis for progressively more accurate estimates for Avogadro's number over the next 100 years. Text books in 1958 gave Avogadro's number as 6.02 x 1023. The current value is 6.022136736 x 1023.

Amadeo Avogadro Avogadro's work was recognized nearly fifty years after he had made his hypothesis. Two years after his death, on July 9, 1856 in Turin, Italy; his colleague showed how the use of Avogadro's law could solve many of the problems in chemistry.

Amadeo Avogadro Standing on the shoulders of giants Gay-Lussac had discovered that all the gases when subjected to an equal rise in temperature, expand by the same amount. Avogadro used his facts to derive his hypothesis.

To Pass the Regents test!!!! How do we use a Mole? Stoichiometry - the study of the quantitative relationships in chemistry To easily convert atomic mass units to grams To understand chemical reactions To Pass the Regents test!!!!

Gases only? ? ? While the original hypothesis was developed from gases. Avogadro’s number is useful for all types of atoms and molecules Gases, Liquids and Solids

How big is a mole? 12 grams for Carbon (C) 197 grams for Gold (Au) 1500 grams for a small protein 50,000 -100,000 grams for a more complex protein

But . . . . . . . . . How big is a mole? It is difficult to imagine such a large number as Avogadro's number. Some idea of its magnitude is given by the following calculations.

But . . . . . . . . . How big is a mole?

BIG ! ! ! If we took 6.02252 x 1023 regular 8.5 x 11 inch sheets of paper And laid them out to cover the entire planet’s surface. Every inch2 of land and water.

BIG ! ! ! We would have enough sheets of paper to cover the entire Earth To a thickness of

Very BIG ! ! ! 71 MILLION SHEETS THICK

71 Million sheets of paper thick Would be a crust of papers over 7 kilometers (4.4 miles) thick

But . . . . . . . . . How big is a mole? Could we try that again?

BIG ! ! ! If we wanted to count 6.02252 x 1023 seconds. And started counting backwards 60 seconds in a minute 3600 seconds in an hour

BIG ! ! ! 86400 seconds in a day 2592000 seconds in a 30 day month 31,557,600 seconds in a year 3.16 x 1013 seconds in a million years We could count backwards to beginning of time. When the universe began 14 billion years ago.

Very BIG ! ! ! Over 1 MILLION times

But . . . . . . . . . How big is a mole? Could we try that again?

BIG ! ! ! If we wanted to get 6.02252 x 1023 chocolate chips. From bags of Chips Ahoy Cookies With over 1000 chips in every bag

BIG ! ! ! With warehouses of cookies each containing 1,000,000 cases of cookies With 48 bags of cookies in each box With ten thousand warehouses in each city

Very BIG ! ! ! We would need 1.25 trillion cities full of warehouses.

But molecules are so small That we can get a Mole of many molecules into small spaces. Like a Mole of water is only 18 grams, or about 2/3 of an ounce. And all gasses, no matter what chemical composition, take up 22.4 liters of space at STP.

So we can work with Moles In many ways

This has been an ECB Production © 2003 Dr. Edward C. Bein