Chapter 12
Chapter 13
Chapter 14
Conceptual
Math
100
What are the IMFs present in methanol? (CH3OH)
LDF, Dipole-dipole, and H bonding
100
Which molecule is most soluble in water?
A: CH3OH
B: CH3CH2CH2CH3
C: CH3OCH3
CH3OH
100
Consider the rate law: rate= k[A]n[B]m and answer the following:
1: Determine the value of n if the rate doubles when [A] is doubled
2: Determine the value of m if the rate decreases by 1/4 when [B] is halved
1: n=1
2: n=2
100
Describe what happens to the solubility of a solid and a gas during the following:
1: The temperature increases
2: The temperature decreases and the pressure increases
3: The pressure decreases and temperature stays the same
1: The solubility of the solid will increase and the solubility of the gas will decrease
2: The solubility of the solid will decrease due to temp decrease and the solubility of the gas will increase
3: The solubility of the solid will stay the same and solubility of the gas will decrease
100
The rate constant for the first-order decomposition of N2O is 3.40 s-1. What is the half-life of the
decomposition?
0.204 s
200
Based on the following data, which substance has the weakest intermolecular forces?
Substance Hvap (kJ/mol)
Argon 6.3
Benzene 31.0
Ethanol 39.3
Water 40.8
Methane 9.2
Argon
200
At 30 C, you add 45 g of NaCl to 100 g of water. Is this solution saturated or unsaturated?
Saturated
200
If rate= k[A][B]2 has an initial rate of 0.0270 M/s, what will the initial rate be if [A] if halved and [B] is tripled?
0.1215 M/s
200
What is the molecularity of the following elementary step?
O3= O2 + O
unimolecular
200
Using the data calculate the average rate of reaction for
- 0s to 155s
- 155s to 466s
t (s) [N2O5]
0 2.272
155 2.061
466 1.695
765 1.404
- 0.00136 M/s
- 0.00118 M/s
300
Find the empirical formula of compound that crystallizes with the atoms distributed as follows:
Element X: 8 atoms at the corners, 1 atom at the body center
Element Z: 24 edge atoms
Element A: 4 face atoms
XZ6A
300
Which aqueous solution has the highest boiling point elevation?
2.5 M of C6H12O6
2.0 M NaCl
1.5 M MgCl2
1.0 M KNO3
1.5 M MgCl2
300
The half-life of iodine-131 is 8.0 days. How long does it take for a sample of iodine-131 to decay to 12.5% of its original level?
24 days
300
You are given 3 plots of data: [A] versus time, ln[A] versus time, and 1/[A] versus time.
The graph demonstrating a straight line for the data is [A] versus time. What order is this reaction based on this information?
Zero-order
300
A solution is made by dissolving 0.854 moles of nonelectrolyte solute in 578 g of benzene. Calculate the freezing point of the solution:
Kf benzene: 5.12 C/m, normal freezing point 5.49 C
-2.07 C
400
Answer the questions of the following molecules:
CH3OH, PCl3, (CH3)2CO, H2
1. Which of these substances has hydrogen bonding as its dominant IMF?
2. Which of these has LDF present?
3. Which of these substances has the greatest solubility in water?
4. Which of these substances as LDF as the strongest IMF?
5: Which of these substances has dipole-dipole as the strongest IMF?
1: CH3OH
2: All have LDF
3: CH3OH
4: H2
5: PCl3 and (CH3)2CO
400
A solution was made by adding 800 g of ethanol to 8000 g of water. How much would this lower the freezing point by?
MM ethanol= 46.07 g/mol
Kf H2O= 1.86
It would lower it by 4.04 C
400
The following set of data was found for the following reaction:
2A + B = C + D
Trial [A] [B] Rate (M/s)
1 0.10 0.10 4.2 x 10-6
2 0.10 0.20 1.7 x 10-5
3 0.30 0.20 1.5 x 10-4
1: What is the order with respect to A?
2: What is the order with respect to B?
3: What is the value of k?
1: 2
2: 2
3: k= 0.042 M-3s-1
400
Place the following compounds in order of increasing (lowest to highest) boiling point.
LiF, N2, CH3CH2NH2
N2<CH3CH2NH2< LiF
400
The first-order decomposition of N2O at 1000 K has a rate constant of 0.76 s-1. If the initial
concentration of N2O is 10.9 M, what is the concentration of N2O after 9.6 s?
1st order equation: ln[A]t=-kt + ln[A]0
7.39 x 10 -3 M
500
What is the enthalpy (heat) change during the process when 100 g of water at 50C are cooled to ice at -30C?
MM water= 18.02
Hfus=6.01 kj/mol
Hvap= 40.67 kj/mol
Cice=2.03 J/g C
Cwater=4.184 J/g C
Csteam=1.84 J/g C
60.36 kJ or 60630 J
500
What is the molality for an aqueous solution that is 25% NaOH by mass?
MM NaOH= 39.99 g/mol
MM water= 18.02 g/mol
m= 8.34 mol/kg
500
The first-order rate constant for the decomposition of a certain antibiotic in water at 30 C is 2.75 yr-1. If a 7.5 x 10-4 M solution of the antibiotic is stored at 30C, what will its concentration be after 4 months?
1st order: ln[A]t= -kt + ln[A]0
3.03 x 10-4 M
500
What determines if a step is rate-determining?
It is the slowest step
500
A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The concentration of Cl in this solution is ________ M
MM CaCl2= 110.98 g/mol
1.12 M