Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chemistry
Unit Activity
Unit 4: The Mole Concept
This Unit Activity will help you meet these educational goals:
STEM— You will use online research to understand scientific reasoning
...
You will use
mathematics to solve real world scientific problems
...
Introduction
In 1811, Amedeo Avogadro proposed 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
...
This hypothesis went on to become the basis of one of the most widely used
constants in chemical measurements, the Avogadro’s number
...
You can find the composition and formulas of unknown
substances and analyze their properties with the help of molar quantities
...
You will also help solve a hypothetical murder mystery by
finding the formula and properties of an unknown substance found at a crime scene
...
Then, answer the following
questions
...
Key search terms: Avogadro’s number, the mole unit, history of mole
1
...
In this account,
include the roles of Gay-Lussac, Avogadro, Cannizzaro, and Perrin
...
The law stated that when two volumes of gases react with one
another to create a third gas, the ratio between the volume of the reactants and the
volume of the product is always made of simple whole numbers
...
It would
take another chemist by the name of Stanislao Cannizzaro to bring Avogadro's
1
© 2013 EDMENTUM, INC
...
By the time those ideas gained traction, he
passed away
...
2
...
687 × 10 ^19
...
3
...
We
say that one mole of a substance is the amount that contains Avogadro’s number of
particles
...
Analyze the theories and definition of both these concepts
...
Type your response here: Avogadro's number was first defined as the number of
atoms in one gram of molecular hydrogen
...
So, in describing a reaction, you know what the proportions atoms or
molecules there are to react with
...
Task 2: The mystery of the unknown substance
A prominent automotive businessman has been murdered in New York
...
The
label on the bottle has fallen off
...
Their suspects include the victim’s business rival,
his lawyer, and a theatre actress
...
One of the CSI technicians has analyzed the liquid using a mass spectrometer and found that
the compound has a molar mass of 58
...
Further analysis has also revealed that the
compound consists of 18 g of carbon, 3 g of hydrogen, and 8 g of oxygen
...
Answer the following questions to find the identity of
the unknown substance
...
What is the percent composition of all the components in the liquid?
2
Type your response here:
C = 18/29 = 62
...
3 %
O = 8 / 29 = 27
...
What is the empirical formula of the compound?
Type your response here: C 0
...
501 O 0
...
What is the molecular formula of the unknown liquid?
Type your response here:
4
...
Go online and figure out the name of this compound
...
Can you identify the killer from this information? How?
Type your response here: Formaldehyde- A highly reactive aldehyde gas formed by
oxidation or incomplete combustion of hydrocarbons
...
Formaldehyde solution (formalin) is considered
a hazardous compound and its vapor toxic
...
Points possible:
Avogadro’s number and the mole: 5 points maximum
3
The mystery of the unknown substance: 5 points maximum
Avogadro’s number and the mole
5 points
History of Avogadro’s number:
Avogadro’s inspiration from GayLussac, Why it was not accepted,
Cannizzaro’s contribution, Perrin’s
finding
Loschmidt’s number and its
significance
The connection between the definitions
of Avogadro’s number and the mole
The mystery of the unknown
substance
5 points
Percent composition
Empirical formula
Molecular formula
Name of the compound, its uses, and
conclusion
4
Self-Checked Activity: For Advanced Understanding
Note: This section may be optional; follow your instructor’s directions
...
The test items will challenge your
knowledge of the unit concepts, help you tie different concepts together, and help you gain
confidence in addressing written response test items
...
Read the directions section carefully
...
Unless directed otherwise, answer the question in an essay form; do not use
bullets, outline format, etc