Explore BrainMass

Explore BrainMass

    Chemical Kinetics

    Calculate Activation Energy

    The second-order rate constant for the decomposition of nitrous oxide (N2O) into a nitrogen molecule and oxygen atom has been measured at different temperatures given below. k(1/M·s) t(°C) 1.87 10-3 600 0.0113 650 0.0569 700 0.244 750 Determine graphically the activation energy for the reaction. I took 1/873 wa

    Rate Constant for a Reaction

    For the reaction given below, the frequency factor A is 8.7 1012 s-1 and the activation energy is 63 kJ/mol. NO(g) + O3(g) NO2(g) + O2(g) What is the rate constant for the reaction at 50°C? I used the equation k=Ae^(-Ea/RT) by plugging in the variables I got 8.5e12. But they say this is significantly off. where did i go

    Exam Review 2 Questions

    Would like to see answers worked out for exam review. Question 1 P(C6H14)/t was found to be -6.2 x 10-3 atm/s for the following reaction: C6H14(g) C6H6(g) + 4H2(g) Determine P(H2)/t for this reaction at the same time. 6.2 x 10-3 atm/s 1.6 x 10-3 atm/s 2.5 x 10-2 atm/s -1.6 x 10-3 atm/s -2.5 x 10-2 atm/s

    Chemical Kinetics and Reactions

    Could you please explain this 1. Compare two chemical reactions,one requiring simultaneous collision of three molecules and the other requiring a collision between two molecules. Assuming all else is equal, which reaction should be faster? Why? and can you give an example. 2. People submerged in very cold water and those t

    Formula of Compound given combustion reaction, dumas method

    A compound contains only C, H, and N. A chemist analyzes it by doing the following experiments. (a) Complete combustion of 35.0 mg of the compound produced 33.5 mg CO2 and 41.1 mg H2O. (b) A 65.2 mg sample of the compound was analyzed for nitrogen by the Dumas method, giving 35.6 mL of dry N2 at 740. torr and 25°C.

    Gen. chem 2 problems in Kinetics

    Please see the attached file for full questions. 1. Consider the following reaction: 2N2O(g) -> 2N2(g) + O2(g) a. express the rate of the reaction with respect to each of the reactants & products. b. In the first 10s of the reaction, .018 mol of O2 is produced in a reaction vessel with a volume of .250L. what is the average

    Factor label method

    How many cm are in 16.25 miles? how many seconds are required for a wave traveling at 600 miles in an hour to go a distance of 700 feet. sound travels approx. at a rate of 1.50 X 10-3 meters per second through water. determine this rate in miles per hour.

    The PCB Concentration in Lake Michigan

    The PCB concentration in Lake Michigan is declining according to a first-order rate law having a rate constant of 0.050 per year. If the PCB concentration in Lake Michigan averaged 0.47 ppt in 1991, what will it be in 2005? In what year will the concentration fall to 0.10 ppt? What is the half-life period of PCBs in this lake? (

    Reaction Kinetics, Rate Laws and Equilibrium

    1. The isomerization of cyclopropane to form propene CH3 - CH CH2CH2 is a first-order reaction. At 760 K, 15 percent of a sample of cyclopropane changes to propene in 6.8 minutes. What is the half-life of cyclopropane at 760 K? 2. Consider the two gaseous equilibria (K1 and K2): SO2(g) + ½O2(g) SO3(g)

    Rates of Radioactive Decay

    A one- milligram sample of Cu-64 (nuclear mass =63.92 amu) has an activity of 3.82*10^3 Ci. 1a) How many atoms are in the sample? b) What is the decay rate in atoms/s? c) What is the rate constant in min-1? d) What is the half-life in minutes? 2) What percentage of Cu-64 will decay in 4.00hr?

    Determining flow rates- volumetric versus mass flow rates

    A flow meter reads 10 liters per minute. The flow is comprised of a 7% solution of water and Chemical A. The % solution is known by Wgt Chemical A/Wgt Chemical A + Wgt of Water Chemical A has a given specific gravity of 2.8 as compared to water...the MW of Chemical A is given as 435 g/mol Therefore, for every 1 liter

    Oil Supply and Reserves

    1. Just to continue using oil at the current rate (not the projected higher exponential rate), we must discover and add to global oil reserves the equivalent of a new Saudi Arabian supply (the world's largest) every 10 years. Do you believe this is possible? If not, what effects might this have on your life and on the life of a

    Reaction Mechanism Based on Rate Expression

    Problem: For the reaction: 2H2(g)+2NO(g)--> N2(g)+2H2O(g) The observed rate expression is: rate=k[NO]^2[H2] Which of the following mechanisms is/are consistent with the overall reaction and the rate expression? a. Single step 2H2 + 2NO --> N2 + 2H2O b. Step 1 H2 + NO --> H2O + N (slow) Step 2

    System of Equations of Integrated Rate Laws and Competing Rates

    Consider two reaction vessels, one containing A and the other containing B. At t = 0, [A]o = [B]o. A and B decompose by first order kinetics with rate constants of kA = 4.50 × 10^-4 s-1 and kB = 3.70 × 10^-3 s-1, respectively. Calculate the time that must pass to reach the condition such that [A] = (1.97)[B].

    Kinetics : Percent Completion of First Order Reaction

    A reaction of the form aA ---> Products (image missing) gives a plot of ln[A] vs time(in seconds) which is a straight line with a slope of -7.35 x 10^-3. Assuming [A]o = 0.0100 M, calculate the time (in seconds) required for the reaction to reach 59.9 percent completion.

    Reaction Kinetics : Half-Life and the Arrhenius Equation

    Knowing the rate constant is 3.46 X 10^-5 s^ at 298 and that energy activation is 1.60 x 10^5 J-mol ^-1. Determine the temperature at which the half life for the 1st order decomposition of dinitrogen pentoxide in carbon tetrachloride to dinitrogen tetroxide and oxygen is 2 hours.

    Kinetics: Concentration of a First Order Reaction

    The 1st order composition of hydrogen peroxide has a rate constant of 7.30 X 10-4 s^-1 at 25 degrees C. Determine the percent of hydrogen peroxide that has decomposed after the first 500 seconds? Since I do not have the initial concentration, I was going to use the half life equation and take the percentage of that. The miss

    Nitrogen Content and Biochemical Oxygen Demand ( BOD )

    We have a wastewater source whose flow is 2000 m3 per day; the stated BOD or bio-chemical oxygen demand in that wastewater is given as 5000 mg/l. We are to use urea (NH2)2CO to provide nitrogen to the wastewater in a specific ratio of 100 parts (BOD) to 5 parts(Nitrogen) --- no more or no less. The mass fraction of N in ur

    Activation Energy and the Arrhenius Equation

    Given that the rate constant is 4.0×10^−4 at 25.0 degrees C and that the rate constant is 2.6×10^−3 at 42.4 degrees C, what is the activation energy in kilojoules per mole?

    Reaction Kinetics : Calculating a Rate Constant

    The following data were acquired in an iodination experiment involving acetone. Trial Volume of 0.0010 ( ) Volume of 0.050 ( ) Volume of 1.0 acetone ( ) Volume of water ( ) Temperature ( ) Reaction time ( ) A 5.0 10.0 10.0 25.0 25.0 130 B 10.0 10.0 10.0 20.0 25.0 249 C 10.0 20.0 10.0 10.0 25.0 128 D 10.0 10.0 20

    Reaction Kinetics : Absorbance of Crystal Violet

    The question is : What is happening to the crystal violet concentration as the absorbance decreases? Choices: a) increases b) decreases c) nothing happens to the crystal violet concentration CRYSTAL VIOLET(1) A KINETICS STUDY -----------------------------------------------------------------

    Reaction Kinetics Lab : Hydrolysis of Aspirin

    Please see the attached files for the fully formatted problems. Use the data attached to work out the order of reaction in terms of rate (calculate the error associated with the determined value) Discuss the MECHANISM, HYBRIDIATION, BOND LENGTHS and REACTION NAME of the process discussed.

    Rate Laws, Rate Constants and Reaction Orders

    Please see the attached file for the fully formatted problems. Question 1 Consider the reaction whose rate at 25 was measured using three different sets of initial concentrations as listed in the following table: 1 0.40 0.010 1.9×10^3 2 0.40 0.020 3.8×10^3 3 0.80 0.010 7.7×10^3 What is the rate law

    Calculating Rate Laws

    Please see the attached file for the fully formatted problems. For the reaction , the initial reaction rate was measured for various initial concentrations of reactants. The following data were collected: Trial ( ) ( ) ( ) Initial Rate ( ) 1 0.10 0.10 0.10 2 0.10 0.10 0.30 3 0.20 0.10 0.10 4

    Reaction Kinetics : Reaction Orders from Concentration and Reaction Times

    The following data were acquired in an iodination experiment involving acetone. Trial Volume of 0.0010 ( ) Volume of 0.050 ( ) Volume of 1.0 acetone ( ) Volume of water ( ) Temperature ( ) Reaction time ( ) A 5.0 10.0 10.0 25.0 25.0 130 B 10.0 10.0 10.0 20.0 25.0 249 C 10.0 20.0 10.0 10.0 25.0 128 D 10.0

    Concentration and Reaction Order

    Solution to be listed in Excel Graphs The initial speed of formation of a substance X depends on the concentration as it follows: C x*103 [M] 5.0 8.2 17 30 Vx, 0*107 [Ms-1] 3.6 9.6 41 130 Find the order of the reaction and the constant of speed. Solution: Let the order of reaction be "m" and constant of speed k. The

    Rate Constant for Reverse Reaction

    The rate constant for the elementary reaction is 7.1 109/M·s at 25°C. 2 NO(g) + O2(g) 2 NO2(g) What is the rate constant for the reverse reaction at the same temperature?

    Rate Law of First Order Decomposition of C4H8

    The rate constant for the first-order decomposition of C4H8 at 500 degrees Celsius is 9.2 e -3 s-1. How long will it take for 10.0% of a 0.100 M sample of C4H8 to decompose at 500 degrees C?