One way I managed to keep an A average on the tests was to make up my own practice test before each exam that covered the chapters we went over. I'd one copy, sans answers of course, and use it to test myself, then I'd grade it afterward, focus on what I missed, then take the whole thing over again. I would do this until I got an A on my own test. For the most part, it worked pretty well. I know a lot of you are probably cramming for your exams right now, so here is a 4-part series of posts with my own practice exams, for you to test against. I hope they help you as much as they helped me.
(quick links to all 4 parts)
Ch. 12 and 13 Practice Test (Solutions and Rates of Reaction)
Chapter 14-16 Practice Test (Part 2: Chemical Equilibrium, Acids and Bases, and Acid-Base Equilibria)
Chapter 17 and 18 Practice Test (Part 3: Solubility and Complex-Ion Equilibria, and Thermodynamics and Equilibrium)
Chapters 19, 20, and 23 Practice Test (Part 4: Electrochemistry, Nuclear Chemistry, and Organic Chemistry)
Ch. 12 and 13 Practice Test
(Solutions and Rates of Reaction)
1. What is the formula for Molality? Moles of Solute
Kg of Solvent
2. What is the formula for Mole Ratio? Moles of [A]
Total Moles of Solution
3. What is the formula for Mass Percent? Mass of Solute x 100%
Mass of Solution
4. What are the Colligative Properties and their respective formulas?
a. Boiling Point ∆Tb = v * Kb * m (molality)
b. Freezing Point ∆Tf = -v * Kf * m (molality)
c. Osmotic Pressure π = v * M (Molarity) * R (0.082058) * T (in Kelvin)
d. Vapor Pressure VP (solution) = Mf (Mole Fraction) * VP (solvent)
5. What affects the solubility between a solute and a solvent?
a. Like dissolves Like
b. Polar vs. Non Polar
c. Magnitude
d. Intermolecular Forces of Attraction
i. London Forces (weakest)
ii. Dipole-Dipole Forces
iii. Hydrogen Bonds (strongest)
6. What factors will affect the Rate of Reaction?
a. Temperature (∆T of +10 deg. C will double the rate of reaction)
b. Surface Area (larger = faster reaction)
c. Concentration of reactants
d. Concentration of Catalyst
e. Ignore Products for this chapter.
7. What is the Rate Law? Rate = k * [A]x [B]y
8. What are the units for K per Reaction Order?
a. 0th Order = k = M/s = x1
b. 1st Order = k[A] = 1/s = x2
c. 2nd Order = k[A][B] = 1/M * s = x4
d. 3rd Order = k[A][B][C] = 1/M2 *s = x8
9. How do you determine the Half Life of a First Order Reaction?
a. Determine K: ln ( [A]t ) = - K*T
( [A]o )
b. Use K to Calculate Half Life T1/2 = ln(2)
K
10. What is Collision Theory? Reactions occur when a collision of the proper orientation occurs with the minimum level of activation energy (Ea).
11. How do you determine Collision Frequency? K = Z * f * p
f = e(-Ea/RT)
e = 2.718
R = gas constant
p = Proper Orientation
12. What is Arrhenius Equation? A way to determine the activation energy by using temperature and rate constant. The formula is:
ln ( K2 ) = Ea * ( 1 – 1 )
K1 R ( T1 T2 )
13. What is a Rate Law Mechanism? A plausible explanation that must meet two criteria:
a. All elementary steps must sum to the overall equation
b. Must be consistent with the rate law for the overall equation.
(edit: Corrected Answer to Question 1, sorry for the typo)
(edit: Corrected Answer to Question 1, sorry for the typo)
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