Explore BrainMass
Share

Chemical Kinetics

Rate Constants and Activation Energy

The rate constants of some reactions double with every 10 degree rise in temperature. Assume that a reaction takes place at 336K and 346K. What must the activation energy be for the rate constant to double as described?

rate law for second order reaction

The rate constant for the second-order reaction given below is 0.80/M·s at 10°C. 2 NOBr(g) ----> 2 NO(g) + Br2(g) (a) Starting with a concentration of 0.080 M, calculate the concentration of NOBr after 13 s. (b) Calculate the half-life when [NOBr]0 = 0.090 M. (c) Find the half-life when [NOBr]0 = 0.044 M

Rate of Reaction for Loss of Iodine

For the chemical reaction given, the rate of loss of Iodine -d[I2]/dt is 0.012 M/min at a particular time during the reaction. What is the rate, d[I-]/dt at which I- is being formed? CH3COCH3 + I2 goes to CH3COCH2I + (I-) + (H+)

Molecularity, Rate Expressions and Rate Determining Step

The hydrogenation of ethylene (C2H4) to ethane (C2H6)is accomplished by the following mechanism: (1) H2 <--> 2H (2) C2H4 + H --> C2H5 (3) C2H5 + H --> C2H6 ------------------------ Net: H2 + C2H4 --> C2H6 Classify the reaction molecularity in each elementary step. If the overall rate expression for the net reaction

Chemical Kinetics, Experimental Measurements and Rate Law

1) Explain the concept of chemical kinetics and the various factors that influence reaction states. 2) Relate experimental measurements to reaction rates and the rate laws. 3) Determine the order of reaction, the rate law, the rate constant, and the rate of concentrations. 4) Solve first-order rate problems.

Dissociation Reaction

Ammonium hydrogen sulfide dissociates into ammonia gas and hydrogen sulfide gas. If we start with a sample of pure NH4HS(s) at 25 degrees Celsius, the total pressure of the gases is 0.658 atm when equilibrium is established. Write an equation for the dissociation reaction and determine the value of Kp. (Use the lowest possi

Kinetics - Reaction

Please see the attached file. 4. The following data were measured for the reaction: BF3 (g) + NH3 (g) -> F3 BNH3 (g) experiment [BF3] (M) [NH¬3] (M) Initial rate (M/s) 1 0.250 0.250 0.2130 2 0.250 0.125 0.1065 3 0.200 0.100 0.0682 4 0.350 0.100 0.1193 5 0.175 0.100 0.0596 a. what is the rate

Orders of Reaction

The rate of the following reaction in aqueous solution is monitored by measuring the number of moles of Hg2Cl2 that precipitate per liter per minute. The data obtained are listed in the table. 2HgCl2 + (C2O4^2-) ----> (2Cl^-) + 2CO2 (g) + Hg2Cl2 (s) Experiment [HgCl2],M ([C2O4]^2-),M Initial rate,m

Determining Partial and Total Pressure: Dimethyl Ether Example

The decomposition of dimethyl ether at 504 degrees Celsius is a first-order reaction with a half-life of 27.0 min. (CH3)2O (g) ----> CH4 (g) + H2 (g) + CO (g) (a) What will be the partial pressure of (CH3)2O (g) after 1.29 h if its initial partial pressure was 596 mmHg? (in mmHg) (b) What will be the total ga

first-order decomposition of sulfuryl chloride

The half-life for the first-order decomposition of sulfuryl chloride at 320 degrees Celsius is 8.75 h. SO2Cl2 (g) -----> SO2 (g) + Cl2 (g) (a) What is the value of the rate constant k, in s^-1? (b) What is the pressure of sulfuryl chloride 2.52 h after the start of the reaction, if its initial pres

Reaction Rates

The rate of the following reaction in aqueous solution is monitored by measuring the rate of formation of (I3^-). The data obtained is listed in the table. (S2O8^2-) + (3I^-) ----> (2SO4^2-) + (I3^-) Experiment ([S2O8]^2-), M ([I]^-),M Initial rate, M s^1- 1 0

concentration of PAN in air

The smog constituent peroxyacetyl nitrate (PAN) dissociates into peroxyacetyl radicals and NO2 (g) in a first-order reaction with a half-life of 32 min. If the initial concentration of PAN in an air sample is 5.9 x 10^14 molecules/L, what will be the concentration 1.05 h later? (in molecules/L)

first-order decomposition of dinitrogen pentoxide

In the first-order decomposition of dinitrogen pentoxide at 335 K, assume we start with a 2.50 g sample of N2O5 at 335 K and have 1.50 g remaining after 109 s. N2O5 (g) -----> 2NO2 + 1/2 O2 (a) What is the value of the rate constant k? (in s^-1) (b) What is the half-life of the reaction? (in s) (c) What mass of N2O5 w

Reactions and Rate Equations

(a) From the rate constant k1 = 3.66 x 10^-3 s^-1 compute the instantaneous rate (r1) of the first-order decomposition of 2.30 M H2O2 (aq). (in mol L^-1 s^-1) (b) From the rate constant k2 = 1.24 x 10^-2 L mol^-1 s^-1 compute the instantaneous rate (r2) of the second-order decomposition of 2.04 M C8H9O3 (l). (in mol L^-1

Reaction Rates

In the reaction A + 2B ----> C + 3D, the rate of disappearance of B is -7.6 x 10^-4 mol L^-1 s^-1. (a) What is the rate of disappearance of A? (in mol/L^-1 s^-1) (b) What is the rate of formation of D? (in mol/L^-1 s^-1) (c) What is the "rate of the reaction"? (in mol/L^-1 s^-1)

decomposition of H2O2

In the reaction 2H2O2 (aq) ------> 2H2O (l) + O2 (g), the initial concentration of H2O2 is 0.2504 mol/L, the initial rate of decomposition of H2O2 is 9.32 x 10^-4 mol L^-1s^-1. What will be [H2O2] at t= 36s?

Steady State Radon Concentration in the Basement of a House

Radioactive radon gas (222Rn) enters an average building at a rate of 4 picocuries per second per square meter of foundation area. Consider a house with a foundation of 200 square meters and a volume of 1000 cubic meters. Assume the house if well designed for energy conservation so that the ventilation rate is low and only one t

Mole Fraction

What is the mole fraction of urea, CO(NH2)2, in a solution prepared by dissolving 31.0 g CO(NH2)2 in 118 mL of water at 20 degrees Celsius (d= 0.998 g/mL)?

Solubility of Alum Amongst Paper By-Products

Problem Statement: Chemical XYZ is added to a substrate at a defined rate of 1.17% of the dry weight of the substrate; paper makers alum (Al2(SO4)3-14H2O) is added to the substrate at a rate of 45% of the Chemical XYZ rate; the dry weight of the substrate is given as 1460 lbs/1000 ft2 The molecular weight of the alum is g

Rate Equation for Atmospheric Oxidation of S(IV) to S(VI)

A) Calculate the liquid phase / gas phase ratio for SO2, HNO3, HCl and H2O2 in a cloud droplet (L= 10-6) and determine which phase dominates. b) Explain why the atmospheric rate of formation of S(VI) in the aqueous phase is given by (Please see attachment for atmospheric rate of formation) where k is the liquid-phase rate

Steady State Pollution Concentration from Box Model for City

1) Consider an urban area (100 km^2) with a temperature profile that decreases linearly with height between 30 degrees C at the surface, and 24 degrees C at 500 m. At 500 m, the temperature increases with height to 30 degrees C at 1000 m. What is the mixing height for this situation? Using a box model for the city, calculate

Five physical chemistry questions.

5) Ozone decomposes to oxygen according to the balance chemical equation below: 2O3 ---> 3O2 If the rate of disappearance of the ozone is -7.2E-4 M/s, what is the rate of formation of oxygen? 6) If 100kJ of heat is added to 54.0 g of water at 100°C, what is the final state of the water? MW H2O = 17.9 g/mole 7) How many

Vmax, Km: Calculation of Kinetic Constants, first order

The initial velocity of an enzyme catalyzed reaction was measured at a serious of different initial substrate concentrations in the table. Find Km (sometimes called Ks)(the half velocity constant) and ...there is moreshow problemThe initial velocity of an enzyme catalyzed reaction was measured at a serious of different initial s

Calculating Reaction Order with an Excess of One Reactant

A+B -> C+D The complete data is as follows: The initial concentration of A is 400 mmol/L and initial concentration of B is 0.4 mmol/L. The following data is for concentration of C in mmol/L at different times T in seconds T sec: 0 120 240 360 Infinity [C] : 0 0.2 0.3 0.35 0.4 Assuming

Reaction data for the reaction of Pt(bipy)Cl2 with ethylenediamine was analyzed to obtain a rate constant and reaction orders. Graphs were produced and calculations performed.

In SXR205 Activity B, the kinetics of the reaction between the square-planar platinum complex dichloro-(2,2'-bipyridine) platinum (II) (Pt(bipy)Cl2) and 1,2-diaminoethane (en) were investigated. In a different study of this reaction, the data in Table 1 were obtained manually using a spectrometer set at a fixed wavelength of 274

Reaction Rates: Example Problem

A(g) + 5/8 B(g) --> C(g) + 3/4 D(g) If C is increasing at a rate of 4.0 mol/L*s, at what rate is B changing? Can you just multiply the rate change of 4.0 mol/L*s by 5/8ths to get the reaction rate. If so I got -2.5 mol/L*s.

Weak Electrolyte Undergoes Ionization

Water is a very weak electrolyte that undergoes the ionization- H2O= H+(aq) + OH-(aq) If k1= 2.4x 10-5 s-1 and k-1 = 1.3 x 10 to the eleventh/M*s What is the equilibrium constant K where K= [H=] [OH-]/[H2O] ? What is the product [H+][OH-] ? What is [H+] ? What is [OH-] ?