🔑 Here are all the KEYS to Exam 1

ChemBook Chapters:
Chapter 0: Stuff You Already Know
Chapter 1: Fundamentals of Chemistry
Chapter 2: Atmosphere, Air, and Gases

Learning Outcomes

Students will know...

1. how to count stuff
2. how to mathematically convert from one type of unit to another utilizing a set of conversion factors
3. the names, formulas, and physical state of the first 10 alkanes
4. Know which elements exist as diatomic molecules
5. the MAIN Metric Prefixes for Chemistry Class as listed in section 10.2 of chembook - it's the last table there
6. how to fully balance a chemical reaction and identify the coefficients
7. how to do composition stoichiometry calculations - figuring out the percent of a specific element in a given compound
8. how to do reaction stoichiometry calculations converting moles to moles and also moles to grams and grams to grams or anything else
9. how to predict product amounts when given arbitrary amounts of reactants - limiting reactant problems (like #20 on HW01)
10. the same outcomes as the two previous ones but with gas moles using the ideal gas law to get pressure or volume of the gas reactants.
11. the 3 primary components and their percentages of dry air
12. how those percentages change when humid air is used
13. the 6 primary pollutants in our air - know names and formulas and/or abbreviations for them
14. the primary sources/causes of those pollutants
15. what methods are in place to help curb the amounts of these pollutants in air
16. how to calculate various gas law values - P, V, T, and n according to the ideal gas law and associated laws
17. how to convert pressure of a gas into number (mole) density
18. what partial pressure is and how to calculate it.
19. how to get mole fraction from partial pressure and total pressure and vice versa
20. how to use the pressure and identity of a gas to calculate its mass density
21. how to convert mass density and pressure into the molecular weight of a gas
22. anything else we learned and did in class, on HW, that I forgot here

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More Help on Exam 1

Jimmy Wadman's* Help Videos on Exam 1 topics.

• Composition Stoichiometry
• Reaction Stoichiometry Easy, Medium, Hard
• Reaction Stoichiometry Limiting Reagent
• Reaction Stoichiometry Example with overview
• Gas Law Stoichiometry
• Full Lecture Rxn Stoich Pt 1
• Full Lecture Rxn Stoich Pt 2

*Jimmy Wadman was a longtime TA/Specialist for the UT Chemistry Department. His videos are meaningful and clear. Have a look if you need a new/different take on all this. We are all teaching the same thing. We each have our own "style".

Formulas YOU should know

The Ideal Gas Law (IGL):

   $PV=nRT$

Gas Laws "contained" in the IGL:

Boyle's Law:    $P_1{V}_1=P_2{V}_2$    (constant n, T)

Charles' Law:    ${\displaystyle \frac{V_1}{T_1}=\frac{V_2}{T_2}}$    (constant n, P)

Avogadro's Law:    ${\displaystyle \frac{V_1}{n_1}=\frac{V_2}{n_2}}$    (constant P, T)

Gay-Lussac's Law:    ${\displaystyle \frac{P_1}{T_1}=\frac{P_2}{T_2}}$    (constant n, V)

Inflate a Tire Law:    ${\displaystyle \frac{P_1}{n_1}=\frac{P_2}{n_2}}$    (constant V, T)

Nobody Does This Law:    $n_1{T}_1=n_2{T}_2$    (constant P, V)

(note that you will be tested on the actual relationships of the physical properties and not the scientist's names)

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and because density (ρ) is m/V and molar mass (M) is m/n, then you also know the molar mass of an ideal gas via:

$$M=\frac{\rho RT}{P}$$

Dalton's Law of Partial Pressures
$$P_{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}}=P_{\mathrm{A}}+P_{\mathrm{B}}+P_{\mathrm{C}}+\cdots$$

mole fraction of gas A:   $x_{\mathrm{A}}=P_{\mathrm{A}}/P_{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}}$

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Practice Problem Sets

Here are two practice problem sets for you to work on and get some experience working through these types of problems.

Composition Stoichiometry Extra Practice.pdf     HTML version

Gas Law Stoichiometry Extra Practice.pdf     HTML version

Sorry, but we do not have any answer keys to these problem. Talk with other students about the problems and try to reach a correct conclusion/answer.

There is even MORE great practice problems (with keys) and helpsheets on the gchem site in Chapter 1 there under "Additional Content > Helpsheets and Worksheets". Here's a direct LINK to that page.

Exam protocol All you need to know about HOW to take our in-class exams.