The Nature of Chemistry
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    • The scientific method
    • Observation and inference
    • Evidence, modelling and prediction
    • Theories and paradigm shifts
    • Cause and effect
    • Accuracy, validity and reliability
    • Reason and imagination
    • Bias and the role of humans in science
    • Communication of science
    • Contrasting with other areas of knowledge
    • (IB TOK outline)
  • Topics
    • Stoichiometry
    • Atomic structure
    • Periodicity
    • Chemical bonding and structure
    • Energetics
    • Chemical kinetics
    • Equilibrium
    • Acids and bases
    • Redox processes
    • Organic chemistry
    • Measurement and data processing
  • IB Options
    • A - Materials
    • B - Biochemistry
    • C - Energy
    • D - Medicinal chemistry
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Topic 1 - Stoichiometric relationships


Activity 1 - Phlogiston

Topic 1.1 - Introduction to the particulate nature of matter and chemical change.
NOS statement 2.3 - "Occasionally, however, a new theory will radically change how essential concepts are understood or framed, impacting other theories and causing what is sometimes called a 'paradigm shift' in science."
Time: 15 min.
Task​: The phlogiston theory explained combustion until the late 1700´s. Watch the video and explain how a simple experiment with a balance and the combustion of a piece of magnesium can disprove the phlogiston theory?
Extension: Which scientists and ideas were responsible for the paradigm shift away from this idea?

Activity 2 - Unit convention

Picture
Topic 1.2 - The mole concept
NOS statement 4.3 - "As well as collaborating on the exchange of results, scientists work on a daily basis in collaborative groups on a small and large scale within and between disciplines, laboratories, organizations and countries." 
Time: 10 min.
Task​: Given the large scale of collaboration in science, a shared language is essential. When using units, we use a convention to ensure that they are dealt with consistently around the world. 
All units seen in the IB use, or are derived from, the 7 base units seen below. You will also see prefixes used to show different magnitudes of a unit. Use the simple rules below to identify the correctly written units (right) and rewrite the incorrect ones.
Rules
  • Always put a space between a value and its unit.
  • Prefix and unit should either both be written in full, or both using their symbol (without a space in both cases).
  • Fully written units should always start with a lowercase letter (units named after people will have a capital letter when the symbol is used).
​SI base units
Picture
Magnitudes
Picture
Questions
  1. 1000Mm
  2. 5 Candela
  3. 25.06 ccd
  4. 94 K
  5. 74888 m seconds
  6. 0.004Moles
  7. 20 hm
  8. 12 μ m
  9. 499 Mega seconds
  10. 2 nano Kelvin
Extension: Why does the SI unit for mass (kg) already have a magnitude (kilo-) attached?

Activity 3 - Theory or law?

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Topic 1.3 - Reacting masses and volumes
NOS statement 2.1/2.2/2.3/2.4 - Theories and laws
Time​: 5 min.
Task: 'Topic 1: Stoichiometric relationships' contains many scientific laws. One of the most important of these is the Ideal Gas Law - PV=nRT. Using this as an example, which of the features below might be able to categorise a law in chemistry?
  • Is a proposed explanation for a phenomenon.
  • Is frequently adapted as new evidence is found.
  • Is assumed to be scientific truth within its parameters.
  • Is not developed from a theory.
  • Can be used to make predictions.
  • Is a mathematical statement about phenomena.
  • Is rarely adapted.
  • Is accepted to be incomplete.
  • Is developed from a theory.
  • Cannot be used to make predictions.

Activity 4 (TOK) - The significance of laws​ in chemistry?

Picture
Topic 1.3 - Reacting masses and volumes
Time​: 10 min.
Task​: Laws in chemistry are statements that are considered 100% accurate in their predictions of chemical changes. The law of the conservation of mass is one example.
  1. Refresh your memory of this law using the link above if you need to.
  2. Consider the consequences in chemistry if this law was proven to be false.
  3. If only 1 group of scientists had evidence suggesting it was false, how would the scientific community respond?


Activity 5 - Gas laws and innovation

Picture
Picture
Topic 1.3 - Reacting masses and volumes
NOS statement 5.6 - Whatever the field of science—whether it is in pure research, applied research or in engineering new technology—there is boundless scope for creative and imaginative thinking.
Time​: 5 min.
Task​: People in a rural area in Bangladesh have begun using half plastic bottles mounted on boards as a form of air conditioning in the harsh summer temperatures. Can you use your knowledge of the gas laws to explain how they might work?
​
How is it set up?: The large open half of the bottle is outside the house and funnels air through the narrow opening of the bottle before it enters the open house.
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  • Home
  • Recent news
  • NOC
    • The scientific method
    • Observation and inference
    • Evidence, modelling and prediction
    • Theories and paradigm shifts
    • Cause and effect
    • Accuracy, validity and reliability
    • Reason and imagination
    • Bias and the role of humans in science
    • Communication of science
    • Contrasting with other areas of knowledge
    • (IB TOK outline)
  • Topics
    • Stoichiometry
    • Atomic structure
    • Periodicity
    • Chemical bonding and structure
    • Energetics
    • Chemical kinetics
    • Equilibrium
    • Acids and bases
    • Redox processes
    • Organic chemistry
    • Measurement and data processing
  • IB Options
    • A - Materials
    • B - Biochemistry
    • C - Energy
    • D - Medicinal chemistry
  • People
  • Answers
    • NOC answers
    • Topics answers