Transcript Acids and Bases Review - Powerpoint

Grade 10 Chemistry
 Cluster 2 – Chemistry in Action
Cultural and Historical Applications of Acid Chemistry
Manitoba Curriculum Outcomes
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Cluster 0- Overall Skills and Attitudes
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Cluster 4 – Chemistry in Action
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S2-0-8d Describe examples of how technologies have evolved in response to
changing needs and scientific advances
S2-0-8e Discuss how peoples of various cultures have contributed to the
development of science and technology.
S2-0-9a Appreciate and respect that science and technology have evolved
from different views held by women and men from a variety of societies and
cultural backgrounds.
S2-2-09 Discuss the occurrence of acids and bases in biological systems,
industrial processes, and domestic applications.
Purpose & Intent - The goal of this lesson is to :
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1. reveal a variety of cultural or historical views of the understanding of acids
and bases .
2. challenge students to critically think, read, and write in the field of
chemistry.
Lesson Overview
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Teacher Notes
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Teachers should adjust and adapt the information and discussion
questions in order to challenge their specific students to think, read,
write, and discuss the relevant issues. As the main goal of this
lesson is to reveal a variety of historical and/or cultural views of acid
chemistry teachers should avoid focusing on the details of chemical
formulas of acid chemistry. The presentations lack of scientific
content is an intended omission.
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students often learn science from one perspective only, not realizing
that the evidence-theory connection of all science is evident in the
thoughtful and purposeful thinking of all cultures.
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Science must be presented in a manner that honors the thoughtful
reasoning evident in all peoples. This is just not affirming the cultural
diversity of the marginalized, but also helping the dominant culture to
realize that other cultures are equally able to reason.
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Last two points: Adapted from Prof. Elizabeth McKinley (University of Auckland)
Lesson Structure
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The lesson includes TWO examples of how acids and
bases have been thoughtfully understood and/or utilized in
a variety of cultures and traditional belief systems
1. Acidic Lichen in the lives of
the Inuvialuit & Gwichin of
Northern NWT &Yukon
2. How acidity may provide a
clue as to the health benefits of
the traditional Chinese diet?
Acid Chemistry and the Inuvialuit &
Gwichin of Northern NWT &Yukon
Caribou and Lichen
Hallway of Aklavik School
NOTE: Caribou have been, and continue to be, central to the lives of
the people of Aklavik
Inuvialuit & Gwichin of
Northern NWT &Yukon
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Recognized that the
migration route of
caribou followed
mountain valleys and
corridors.
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Migration of caribou is
influenced by lichen
abundance.
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One lichen today is
called caribou ‘moss’ –
Cladina
rangiferina
What does all this have to do with Acids?
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1. Migration of Caribou
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Lichens are very acidic
and most are not
consumable
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Cladina rangiferina is
not as acidic as other
lichens and therefore
palatable for caribou
Migration of Caribou are
determined by the
growing seasons of the
Cladina rangiferina
Yukon & NWT has TONS of
lichens but not all ‘preferred’
‘most preferred’
by caribou
Hard to distinguish between
them by appearance
Not as ‘preferred’ by
caribou
What does all this have to do with Acids?
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2. Colorant for clothes
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Acidic stomach contents of
caribou (with lichen) used
to alter colours of plants for
dyes – dark to light colours
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Plant dyes behave like
indicators
“soapberries” used to alter
colour of plants
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- especially flowers - for
dyes- light to dark colours
Example of Colorants
This color is not
found anywhere in
nature in Yukon &
NWT
BUT…when certain
material behave
like indicators and
turn yellow in the
presence of an acid
of a specific pH
(lichen contents of
caribou stomach)
Traditional Chinese Medicine
Yin and Yang of Fad Diets?
Yin and Yang foods
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Traditional Chinese beliefs
include two opposing
principles Yin and Yang which
regulate life
this extends and influences
many Asian diets as there is a
belief that some foods are Hot
(yang) or Cold (yin)
It is believed that these foods
(Hot/yang & Cold/yin) need to
be consumed in balance for a
healthy diet
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HOT FOODS
believed to raise body
heat and create tension
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Beef, chicken, eggs,
mutton
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COLD FOODS
believed to cool body
heat and reduce
tension
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Many vegetables
Neutral foods
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are believed to contain
equal parts yin and
yang and therefore
neither reduce or
increase body
temperature
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Brown rice, wheat,
beans, some kinds of
nuts
Traditional Chinese Medicine
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Recent studies in diet have aimed to investigate the
scientific merit of the traditional Hot/Cold Chinese
diet.
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Some recent studies have found that many:
 hot foods are “acid forming” foods and result in lower
internal pH of the body (detected in urine samples)
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As a result minerals from bones leach into the body to act
as a buffer to control acidity contributing to Osteoporosis
Lower internal pH has been linked to many other diseases
 Breast cancer, high blood pressure, heart disease,
diabetes, etc
cold foods are “alkaline forming” foods and contribute to
a more alkaline internal pH
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An alkaline internal pH reduces risk of many diseases
Conclusion – links between Traditional Chinese
Medicine and recent science research
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it is accepted that human health is dependant on
an internal acid-base balance
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therefore there is growing interest and support for further
research regarding the Hot/Cold diet
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Example  how it is correlated with acid forming and
alkaline forming foods
other aspects of traditional Chinese medicine are also
becoming the focus of increasing research
Discussion Questions & Extension Activities
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Acid Chemistry and the Inuvialuit & Gwichin of Northern NWT &Yukon
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Note how the role of the lichen in the migration of the caribou and the uses
of the lichen as a colorant is solely based upon its specific acidic properties.
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Research to find how other cultures have made sense, applied, or utilized
acids and/or bases.
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Example How Aboriginal peoples found a treatment for scurvy (using ascorbic
acid)
Yin and Yang of Fad Diets?
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Many immigrants of Asian decent may still understand or integrate principles
of Hot and Cold foods into their personal diets. Find and interview some of
these people to give you a fuller understanding.
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Note: Remember it is only current research that is showing a possible link between
acid/alkaline forming foods and Hot/Cold foods. Most of these people will not
explain or discuss their diets using acid/alkaline terminology or understanding.
Research the “Mediterranean diet” which is commonly regarded to be one of
the healthiest diets in the world. What principles about the Mediterranean
diet are in sync with concepts discussed in this presentation?