The+Mole



Chemistry Units: The Mole

What is a "mole"? Is it a furry animal with a strange nose? Is it a spy? Is it a benign dark spot on skin? Is it a term for a certain amount of something? Yes, yes, yes, and yes! So what are we going to do with it? ...

Grade Level: 10-11

Unit: Chemistry – The Mole

Lesson Objectives:
 * Student will understand the concept of the mole as a term.
 * Student will be able to identify usage of moles in empirical measures.
 * Student will be able to show memory of the terms: mole, molar, and molarity.
 * Student will demonstrate mathematical understanding of molar ratios.
 * Student will navigate the web and other tools to find resources suitable to express said understanding of the use of the mole.

Time Required to complete this lesson: One session

Title of lesson: A Scavenger Hunt for the Mole

Description of lesson: A scavenger hunt of sorts, with a list and clues (and particular web sites) provided to guide the students through an understanding of the mole and its uses in chemistry.

Assignment: Complete the questions and tasks included in the scavenger hunt.

Resources/materials needed: Classroom, textbook, and computer lab (access to outside web).

Technology used: Internet searches, navigation.

The technology used in this lesson changes the teaching / learning in this way: By learning to navigate succinctly, students will learn a valuable skill in time management as well as gain an understanding of the mole and its uses in chemistry.

=Below follows the basic scavenger hunt idea for the lesson...=

We’re going on a virtual scavenger hunt today. “A scavenger hunt?!” “What’s that?” For simplicity’s sake today it will be defined by the following activity wherein you, the student, will be directed by clues found here in these instructions and elsewhere, to and through a series of questions and answers, until you have found all the clues and can solve a final question. It will be a virtual hunt because you will not need to physically //go// anywhere, only by visiting the virtual landscape of the internet from your computer. You are free to use your memory, your textbooks, and the internet to answer these questions. Some will have specific links to help you. The questions for which you must write out an answer will be highlighted in blue and typed in verdana font.

To begin, we will start with some scientific concepts you should now be familiar with. Atoms and Elements, how much do they weigh – how much mass do they have? How can we measure them when they are so fantastically small? One could put millions of them on the head of a pin and still not be able to see them.

If we wrote out the digits of the mass of one hydrogen atom it would look like this: 0.000 000 000 000 000 000 000 000 001 67kg. [In scientific notation: 1.67 x 10 ^ – 27] …a mind bogglingly small number. One million of them would still be a supremely small mass: 0.000 000 000 000 000 000 001 67kg. 0.000 000 000 000 000 001 67kg would be a billion of them! How would you write out the mass of a billion billion hydrogen atoms? 1.)

There has to be a better way to count them, and measure them…

That way is to make the units large enough to keep the useable numbers manageable. Enter, Avogadro’s Number. Named in honor of Amadeo Avogadro, an Italian scientist of the early 19th century who noted that the number of particles of any gas were equal to the number of particles of any other gas of the same volume (standard temperature and pressure). This number is 6.022 x 10 ^ 23.

As it turns out, 6.022 x 10 ^ 23 of something is called a mole. In a similar fashion, 12 of something is called a dozen,

and 20 of something is a score.

Abraham Lincoln used the term score when recounting a bit of history during his Gettysburg Address. How would you write out the number he used? 2.)

What can we do with a mole? The scientific term is used often to describe how much of something we have, with general solutions, acids, and bases being the materials we will use the most.

How is the mole defined by the international scientific community (Hint: SI is the acronym for the international system of units)? 3.)

What does //that// mean, you say? Try rewriting that definition in more layman terms (meaning to use simpler words). 4.)

Hint: Where could we find this information? What does your textbook say? What is atomic weight? How many grams should 1 mol of Hydrogen gas weigh? 5.)

Hint: Remember that hydrogen, as well as nitrogen, oxygen, and fluorine gases are all diatomic – meaning there are two atoms bonded together for each molecule of gas.

Give at least one good reason, ie. what contribution(s) did he make, that later scientists decided to honor Mr. Avogadro with the term, Avogadro’s Number? 6.)

Hint: Which kinds of websites would have the best information to help us decide why others decided to honor this scientist? Would an encyclopedia or biographic style site, or a news and/or media site be more suitable? Would a technical or engineering website be overkill? How about college or university websites? At the bottom of this lesson are several websites that you can use to navigate around the web. Or, as always, feel free to discover more on your own (on your own time – so to speak).

7. Which of the following masses has more moles? a.) 1 gram of hydrogen gas b.) 0.001 kg of hydrogen gas c.) 12,000 molecules of hydrogen gas d.) 6.02 x 10^23 molecules of hydrogen gas

8. Which of the following masses has more moles? a.) 10 kg of hydrogen gas b.) 10 kg of oxygen gas c.) 10 kg of nitrogen gas d.) 10 kg of sand

9. Explain in your own words why carbon is used to define the mole rather than hydrogen.

10. How does the term mole relate to the term molarity?

Hint: Check out the base SI units versus derived SI units…

Hold down the control key while clicking on these links to open them in a new window rather than over this page... [] - short history of scientific organization/standardization of terms. [] - concise definitions by “Professor Mole”. [] - self explanatory website with a dictionary/encyclopedia style of organization. [] - another website with different types of explanations. Generates pop ups though. [] - “All about Avogadro’s Number and the mole”.