Interpretation:
The rate law and the rate constant for the gas-phase reaction of phosphine with diborane have to be determined.
Answer to Problem 13.42QE
Rate law for the given reaction is
Explanation of Solution
The reaction between phosphine and diborane to produce
Relative concentration of the reactant is determined by dividing the concentration of each reactant by the smallest concentration of the reactant. Relative rate of the reaction is determined by dividing the rate of the reaction by the smallest rate that is obtained from the experimental data.
The relative concentration of
Experiment | Initial | Initial | Initial rate of the reaction | Relative | Relative | Relative rates of the reaction |
From the above table, it is found that in experiments 1, and 2, the concentration of diborane remains constant while the relative rate of the reaction increases in relative manner as the concentration of
From the above table, it is found that in experiments 3, and 4, the concentration of phosphine remains constant while the relative rate of the reaction increases in relative manner as the concentration of
Rate law:
Rate law is the relationship between the concentration of the reactants and the rate of the reaction. The rate law equation is given as the rate of the reaction that is directly proportional to the product of the reactant concentration that is raised to the power of the respective reactant coefficient. Therefore, the rate law for the given reaction is as follows;
Where,
Rate constant:
The rate constant for the reaction can be calculated from the rate law using the initial concentration of the reactants as shown below;
Rearranging the above equation in order to calculate the rate constant;
Substituting the values for rate and the concentration of the reactants in the above equation, the rate constant of the reaction is calculated as shown below;
Therefore, the rate constant for the reaction is
Want to see more full solutions like this?
Chapter 13 Solutions
Chemistry: Principles and Practice
- The Raschig reaction produces the industrially important reducing agent hydrazine, N2H4, from ammonia, NH3, and hypochlorite ion, OCl−, in basic aqueous solution. A proposed mechanism is Step 1: Step 2: Step 3: What is the overall stoichiometric equation? Which step is rate-limiting? What reaction intermediates are involved? What rate law is predicted by this mechanism?arrow_forwardThe decomposition of iodoethane in the gas phase proceeds according to the following equation: C2H5I(g)C2H4(g)+HI(g) At 660. K, k = 7.2 104 sl; at 720. K, k = 1.7 102 sl. What is the value of the rate constant for this first-order decomposition at 325C? If the initial pressure of iodoethane is 894 torr at 245C, what is the pressure of iodoethane after three half-lives?arrow_forwardAt 573 K, gaseous NO2(g) decomposes, forming NO(g) and O2(g). If a vessel containing NO2(g) has an initial concentration of 1.9 102 mol/L, how long will it take for 75% of the NO2(g) to decompose? The decomposition of NO2(g) is second-order in the reactant and the rate constant for this reaction, at 573 K, is 1.1 L/mol s.arrow_forward
- The initial rate ( [NO]/ t] of the reaction of nitrogen monoxide and oxygen NO(g) + 2O2(g) NO2(g) was measured for various initial concentrations of NO and O2 at 25 C. Determine the rate equation from these data. What is the value of the rate constant, k, and what are its units?arrow_forwardSucrose, a sugar, decomposes in acid solution to give glucose and fructose. The reaction is first-order in sucrose, and the rate constant at 25 C is k = 0.21 h1. If the initial concentration of sucrose is 0.010 mol/L, what is its concentration after 5.0 h?arrow_forwardWrite a rate law for NO3(g) + O2(g) NO2(g) + O3(g) if measurements show the reaction is first order in nitrogen trioxide and second order in oxygen.arrow_forward
- Many biochemical reactions are catalyzed by acids. A typical mechanism consistent with the experimental results (in which HA is the acid and X is the reactant) is Step 1: Step 2: Step 3: Derive the rate law from this mechanism. Determine the order of reaction with respect to HA. Determine how doubling the concentration of HA would affect the rate of the reaction.arrow_forwardFor the reaction of iodine atoms with hydrogen molecules in the gas phase, these rate constants were obtained experimentally. 2I(g) + H2(g) 2HI(g) (a) Calculate the activation energy and frequency factor for this reaction. (b) Estimate the rate constant of the reaction at 400.0 K.arrow_forwardThe catalyzed decomposition of hydrogen peroxide is first-order in [H2O2]. It was found that the concentration of H2O2 decreased from 0.24 M to 0.060 M over a period of 282 minutes. What is the half-life of H2O2? What is the rate constant for this reaction? What is the initial rate of decomposition at the beginning of this experiment (when [H2O2] = 0.24 M)?arrow_forward
- Hydrogen peroxide, H2O2(aq), decomposes to H2O() and O2(g) in a reaction that is first-order in H2O2 and has a rate constant k = 1.06 103 min1 at a given temperature. (a) How long will it take for 15% of a sample of H2O2 to decompose? (b) How long will it take for 85% of the sample to decompose?arrow_forwardUrea, (NH2)2CO, can be prepared by heating ammonium cyanate, NH4OCN. NH4OCN(NH2)2CO This reaction may occur by the following mechanism: NH4++OCNkk1NH3+HOCN(fast,equilibrium)NH3+HOCNk1(NH2)2CO(slow) What is the rate law predicted by this mechanism?arrow_forward
- Chemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781285199023Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning