EM spectrum
What is the difference bw avg rate, initial rate, and instantaneous rate?
instantaneous - specific point in time; initial - instantaneous rate as rxn starts; avg - avg of instantaneous rates over time period
What is the difference bw avg rate, initial rate, and instantaneous rate?
instantaneous - specific point in time; initial - instantaneous rate as rxn starts; avg - avg of instantaneous rates over time period
If E is 3600 M-1cm-1 and the absorption of solution measures 0.650, what is the concentration?
1.80*10^-4M
How will the rate of reaction change for the process: CO(g)+NO2(g)⟶CO2(g)+NO(g) if the rate law for the reaction is rate=k[NO2]^2?
(a) Dec the pressure of NO2 from 0.5atm to 0.250atm?
(b) Inc the [ ] of CO from 0.01M to 0.03M?
(a) process reduces rate by factor of 4
(b) not affected, since it does not appear in the rate law
The rxn A --> B + C is second order in A. When [A]o is 0.234M, the rxn is 34.9% complete in 69.4 seconds. Calculate the value of the rate constant. What will [A] be after 122 seconds?
k = 0.0330M-1s-1
[A] = 0.1205M
If the frequency of a photon is 5.09*10^14 Hz, what is the energy (KJ) of one mole of photons?
203 KJ
5Br-(aq) + BrO3-(aq) + 6H+(aq) --> 3Br2(aq) + 3H2O(l). If the rate of disappearance of Br-(aq) at a particular moment during the rxn is 3.5*10^-4 M/s, what is the rate of appearance of Br2(aq) at that moment?
2.1*10^-4
A solution shows a transmittance of 20%, when taken in a cell of 2.5cm thickness. Calculate its concentration if the molar absorption coefficient is 12000M-1cm-1.
A = 0.698
c = 2.33*10^-5M
2NO(g) + Cl2(g) --> 2NOCl(g)
[NO] | 0.50 | 1.00 | 1.00
[Cl2] | 0.50 | 0.50 | 1.00
Rate | 1.14 | 4.56 | 9.12
What is the rate law? Rate constant?
rate = k[NO]^2 [Cl2]
k = 9.12
HI --> H2 + I2
*make sure to check stoichiometry
Springfield's "Classic Rock" radio station broadcasts at a frquency of 102.1 MHz. What is the length of the radio wave in meters?
2.938m
Cl2(g) + F2(g) --> ClF3(g). Write the rate of rxn.
*make sure to check if equation is balanced
A solution containing 4.48ppm KMnO4, had a %transmittance of 30.9% in a 1.00cm cell at 520nm. Calculate the molar absorptivity of KMnO4 at 520nm. (MW=158.034)
c = 2.84*10^-5M
A = 0.510
E = 1.80*10^4 M-1cm-1
Hydrogen peroxide decomposes into water and oxygen in a first-order process. At. 20.0*C, the half-life for the rxn is 3.92*10^4 seconds. If the initial concentration of hydrogen peroxide is 0.52M, what is the concentration after 7.00 days (6.048*10^5s)?
k = 1.77*10^-5
[A] = 1.17*10^-5
A compound decomposes by a first-order process. If 25.0% of the compound decomposes in 40 minutes, the half-life of the compound is...
96.37 min
A beam of light has a wavelength of 506nm. What is the frequency of the light?
5.93*10^14 Hz
2A --> B
T(s) | 0 | 5.0 | 10.0 | 15.0 | 20.0 | 25.0 | 35.0
[A] (M) | 1.00| 0.775 | 0.625 | 0.465 | 0.360 | 0.285 | 0.230
Determine the avg rate of disappearance of A bw 0.0s and 10.0s, and bw 10.0s and 20.0s.
0.0375M; 0.0265M
What is the absorbance for a solution with a concentration of 0.0024M and E of 313M-1cm-1, with a path length of 2.00cm? What is the %transmittance?
A = 1.5024
T = 3.1%
Calculate the half-life of potassium-43 assuming it follows second-order kinetics with a rate constant of 8.634*10^-6 and starting with 4M potassium.
28955.29
What is the frequency of radiation whose wavelength is 1.73 nm?
1.73*10^17
Blue light has a frequency of 6.98*10^14 Hz. Find its wavelength in nm.
4.30*10^-7m or 430nm
3ClO- --> 2Cl- + ClO3-
In 2 liters of solution.
t | ClO- mol | Cl- mol | ClO3- mol
0 | 2.4 | 0 | 0
100 | 1.8 | 0.4 | 0.2
ClO- ==> 0.003M/s
Cl- ==> 0.002M/s
ClO3- ==> 0.001M/s
If a 1.00*10^-4M solution has an absorbance of 0.139 at a wavelength of 350nm, what is the molar absorptivity?
E = 1390M-1cm-1
A zeroth order rxn is of the form aA --> bB. When the [A]o is 0.897M the [A] is 0.553M after 82.4 seconds. What is the half-life of this rxn when the [A]o is 0.477M?
k = 0.004175
t1/2 = 57.12 seconds
What is the wavelength of radiation that has frequency 9.83x10^9 s-1?
0.03