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Chemistry LibreTexts

Exercises

  • Page ID
    54335
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    Section 1-1

    Q1-1

    What previous chemistry experiences (courses or other) have you had?

    Q1-2

    Why are you taking this course? (check all that apply)

    __Required for your major

    __An elective

    __Because you find chemistry fascinating

    __Other

    Please explain below:

    Q1-3

    What do you think chemistry is about?

    Q1-4

    If you have taken a chemistry course before, what topics do you remember? (Please explain)

    Q1-5

    What do you think you will learn in this course?

    Q1-6

    What would you like to learn about in chemistry if you had the choice?

    Q1-7

    If you are required to take this course – why do you think it is required?

    Q1-8

    What would you like to do after graduation? (Where do you see yourself in 10 years?)

    Section 1-2

    Q2-1

    Give an example of a “scientific” question. Explain why you think it is scientific.

    Q2-2

    Give an example of a non-scientific question. Explain why you think it is non-scientific.

    Q2-3

    What is the difference between the two? How did you make this distinction?

    Q2-4

    What makes a theory scientific (as opposed to a good idea that you came up with on the spur of the moment)?

    Q2-5

    What evidence do you know of that you could use to justify the existence of atoms?

    Section 1-3

    Q3-1

    What do you know about atoms? (Make a list)

    Q3-2

    Which has atoms in it? Explain why you do or do not believe each one has atoms.

    Gold,

    Air,

    Heat,

    Cells (from your body)

    Q3-3

    Which is the smallest?

    A. an atom B. a cell

    C. a molecule D. an electron

    E. it depends

    Justify your answer

    Q3-4

    How big do you think an atom is? How many atoms would fit on a pin-head?

    Q3-5

    Can you provide any direct evidence for the existence of atoms?

    Q3-6

    Do you come across isolated atoms in your daily life?

    Section 1-4

    Q4-1

    Why do you think we use models (either physical or mental) in chemistry?

    Q4-2

    Why do you think we use models (either physical or mental) to represent atoms?

    Q4-3

    Is one model more correct than another?

    Q4-4

    Are some models better suited for some purposes than others?

    Section 1-5

    Q5-1

    What would the distribution of alpha particles, relative to the incident beam, look like if the positive nucleus took up the whole atom (sort of like the plum pudding)? Draw a graph and explain:

    ______________________________________________________________________________

    0° 360°

    Q5-2

    What if it took up 50%? Draw a graph and explain:

    _____________________________________________________________________________

    0° 360°

    Q5-3

    What does the distribution of alpha particles actually look like (recall that 1 in every 8000 particles were deflected). Draw a graph and explain:

    _____________________________________________________________________________

    0° 360°

    Q5-4

    How would Rutherford’s experimental results have differed if he had used electrons or neutrons?

    Section 1-6

    For Thompson and Rutherford’s experiments:

    Thompson

    Rutherford

    What was the claim?

    Raw Data / Observations

    Evidence (how the data are explained)

    Theory/Model

    Picture of model

    Section 1-7

    Q7-1

    What do you think energy is?

    Q7-2

    What is potential energy? Please provide an example?

    Q7-3

    What is kinetic energy? Please provide an example?

    Q7-4

    At the atomic level – what do you think potential energy is?

    Q7-5

    At the atomic level – what do you think kinetic energy is?

    Section 1-8

    Read: p 42- 49 in Text

    Go to:

    Page 1: Watch the simulation on page 1 Read about London dispersion forces.

    Page 2 and 3 (click next at the bottom of the page)

    Q8-1

    What kinds of energy do the various energy “meters” and graphs record? What is the relationship between all these types of energy?

    Q8-2

    Draw a picture of the potential energy change as the two helium atoms approach each other. Label the place where the two atoms would be most stable.

    Q8-3

    Why does the potential energy go down as the atoms approach? (Read in text)

    Q8-4

    What happens to the kinetic energy as the helium atoms approach? Why?

    Q8-5

    What happens to the total energy as the helium atoms approach? Why?

    Section 1-9

    Q9-1

    In this box using a circle to represent each He atom, draw what you think solid He would look like. (use ~20 He atoms)

    Q9-2

    In this box using a circle to represent each He atom, draw what you think liquid He would look like. (use ~20 He atoms)

    Q9-3

    In this box using a circle to represent each He atom, draw what you think gaseous He would look like. (use ~20 He atoms)

    Q9-4

    What is preventing the He atoms from flying apart? (i.e. why do they stick together?)

    Q9-5

    What happens when you add thermal energy (increase the temperature) to the Helium atoms? Why does this happen?

    Q9-6

    If solid He in a container is heated (for example by placing the container on a heated block), the solid will melt and then evaporate. Draw a diagram showing how the energy from the container is transferred to the He atoms. Be sure to write your explanation of your picture as well.

    Q9-7

    How do the He atoms “know” that the temperature is rising?

    Q9-8

    Compared to Ne do you think the London Dispersion Forces between Xe atoms are

    A. Larger B. Smaller C. The same?

    Why – what is the basis of your prediction?

    Q9-9

    Compared to Ne do you think the melting point of Xe is

    A. Larger B. Smaller C. The same?

    Why – what is the basis of your prediction?

    Section 1-10

    Q10-1

    Q10-2

    Section 1-11

    Go to

    And click through to pages 6, 7 and 8 to the hydrogen interactions

    Here we are looking at the interactions between two H atoms (rather than two He atoms). The controls are very similar to pages 2-4. This simulation shows the formation of an H2 molecule, by forming a covalent bond between the two H atoms.

    Q11-1

    Click on the “show He potential” button. What are the differences between the H potential and the He potential? What do the two curves tell you about the magnitude of the interaction of 2 H atoms compared with 2 He atoms?

    Q11-2

    Using the information from the graphs, which interaction do you think would take the most energy to overcome (the interaction between two He atoms or the interaction between two H atoms)? Please explain your reasoning.

    Section 1-12

    Q12-1

    Helium melts around 1K and boils around 4K, while hydrogen melts around 14K and boils around 20K, but the hydrogen molecules do not form hydrogen atoms until the temperature reaches over 6000K (as shown on page 8 of the simulation).

    For each – draw a molecular level picture and then explain how they are similar and different.

    A) Draw a picture of what helium looks like below 1K

    B) Draw a picture of what helium looks like at 3K

    C) Draw a picture of what helium looks like at 20K

    D) Draw a picture of what hydrogen looks like at 1K

    E) Draw a picture of what hydrogen looks like at 15K

    F) Draw a picture of what hydrogen looks like at 200K

    G) Draw a picture of what hydrogen looks like at 7000K

    Section 1-13

    In preparation for Test I, read chapter 1 one of the text.

    QA

    What are the most important concepts covered in chapter one (the big ideas)? - Make a list of at least five of the important ideas (one two lines for each idea)

    QB

    For each idea – write a question that would show that you understand this concept. (It can be in any form – multiple choice, short answer, drawing – use more paper if you need to)


    Exercises is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts.

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