Homework 3 (Due 4/11/16)
- Page ID
- 47371
Name: ______________________________
Section: _____________________________
Student ID#:__________________________
Q3.1
Describe how graphical methods can be used to determine the order of a reaction and its rate constant from a series of data that includes the concentration of A at varying times.
Q3.2 (New)
A study of the rate of the reaction represented as \(2A⟶B\) gave the following data:
Time (s) | 0.0 | 5.0 | 10.0 | 15.0 | 20.0 | 25.0 | 35.0 |
[A] (M) | 1.00 | 0.952 | 0.625 | 0.465 | 0.370 | 0.308 | 0.230 |
- Determine the average rate of disappearance of A between 0.0 s and 10.0 s, and between 10.0 s and 20.0 s.
- Estimate the instantaneous rate of disappearance of A at 15.0 s from a graph of time versus [A]. What are the units of this rate?
- Use the rates found in parts (a) and (b) to determine the average rate of formation of B between 0.00 s and 10.0 s, and the instantaneous rate of formation of B at 15.0 s.
Q3.3
Compounds A and B both decay by first-order kinetics. The half-life of A is 20 minutes and the half-life of B is 48 minutes. If a container initially contains equal concentrations of compounds A and B, after how long will the concentration of B be twice that of A?
Q3.4
Nitrosyl chloride, NOCl, decomposes to NO and Cl2.
\[\ce{2NOCl}(g)⟶\ce{2NO}(g)+\ce{Cl2}(g)\]
Determine the rate equation, the rate constant, and the overall order for this reaction from the following data:
[NOCl] (M) | 0.10 | 0.20 | 0.30 |
Rate (mol/L/h) | 8.0 × 10−10 | 3.2 × 10−9 | 7.2 × 10−9 |
Q3.5
Hydrogen reacts with nitrogen monoxide to form dinitrogen monoxide (laughing gas) according to the equation:
\[\ce{H2}(g)+\ce{2NO}(g)⟶\ce{N2O}(g)+\ce{H2O}(g)\]
Determine the rate equation, the rate constant, and the orders with respect to each reactant from the following data:
[NO] (M) | 0.30 | 0.60 | 0.60 |
[H2] (M) | 0.35 | 0.35 | 0.70 |
Rate (mol/L/s) | 2.835 × 10−3 | 1.134 × 10−2 | 2.268 × 10−2 |
Q3.6
Use the data provided to graphically determine the order and rate constant of the following reaction:
\[\ce{SO2Cl2 ⟶ SO2 + Cl2}\]
Time (s) | 0 | 5.00 × 103 | 1.00 × 104 | 1.50 × 104 | 2.50 × 104 | 3.00 × 104 | 4.00 × 104 |
[SO2Cl2] (M) | 0.100 | 0.0896 | 0.0802 | 0.0719 | 0.0577 | 0.0517 | 0.0415 |
Q3.7
Some bacteria are resistant to the antibiotic penicillin because they produce penicillinase, an enzyme with a molecular weight of 3 × 104 g/mol that converts penicillin into inactive molecules. Although the kinetics of enzyme-catalyzed reactions can be complex, at low concentrations this reaction can be described by a rate equation that is first order in the catalyst (penicillinase) and that also involves the concentration of penicillin. From the following data: 1.0 L of a solution containing 0.15 µg (0.15 × 10−6 g) of penicillinase, determine the order of the reaction with respect to penicillin and the value of the rate constant.
[Penicillin] (M) | Rate (mol/L/min) |
---|---|
2.0 × 10−6 | 1.0 × 10−10 |
3.0 × 10−6 | 1.5 × 10−10 |
4.0 × 10−6 | 2.0 × 10−10 |