Question

The decomposition reaction of NOBr is second order in NOBr, with a rate constant at 20°C...

The decomposition reaction of NOBr is second order in NOBr, with a rate constant at 20°C of 25 M-1 min-1. If the initial concentration of NOBr is 0.025 M, find

(a) the time at which the concentration will be 0.010 M.


(b) the concentration after 145 min of reaction.

Homework Answers

Answer #1

a)

we have:

[NOBr]o = 0.025 M

[NOBr] = 0.01 M

k = 25 M-1.min-1

use integrated rate law for 2nd order reaction

1/[NOBr] = 1/[NOBr]o + k*t

1/(0.01) = 1/(0.025) + 25*t

100 = 40 +25*t

25*t = 60

t = 2.40 min

Answer: 2.40 min

b)

we have:

[NOBr]o = 0.025 M

t = 145.0 min

k = 25 M-1.min-1

Given:

[NOBr]o = 0.025 M

use integrated rate law for 2nd order reaction

1/[NOBr] = 1/[NOBr]o + k*t

1/[NOBr] = 1/(0.025) + 25*145

1/[NOBr] = 40 + 25*145

1/[NOBr] = 3665

[NOBr] = 2.73*10^-4 M

Answer: 2.73*10^-4 M

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
For the reaction 2 NOBr(g)----> 2 NO(g) + Br2(g) the rate law is second order in...
For the reaction 2 NOBr(g)----> 2 NO(g) + Br2(g) the rate law is second order in NOBr with a rate constant of 8.50 x 10-2 M-1·s-1 at 35°C. If the initial concentration of NOBr is 1.00 M, how many seconds does it take for [NOBr] to decrease to 0.10 M? A) 47 seconds B) 72 seconds C) 106 seconds D) 163 seconds E) 224 seconds The answer is C (106 seconds) how do you get this? Please be detailed and...
The thermal decomposition of acetaldehyde, CH3CHO --> CH4 + CO, is a second-order reaction. The rate...
The thermal decomposition of acetaldehyde, CH3CHO --> CH4 + CO, is a second-order reaction. The rate constant is 1.55x10-4 M-1s-1 at 25oC. If the initial concentration of CH3CHO is 0.250M. What will the concentration be after 2.50 hours?
The decomposition of hydrogen peroxide (H2O2) is a first order reaction with a rate constant 1.8×10-5...
The decomposition of hydrogen peroxide (H2O2) is a first order reaction with a rate constant 1.8×10-5 s -1 at 20°C. (a) What is the half life (in hours) for the reaction at 20°C? (b) What is the molarity of H2O2 after four half lives if the initial concentration is 0.30 M? (c) How many hours will it take for the concentration to drop to 25% of its initial value? *Help please!!!*
The rate constant for the first-order decomposition of a compound A in the reaction 2 A...
The rate constant for the first-order decomposition of a compound A in the reaction 2 A  P is k, =3.56 x 10-7 s-1 at 25°C. What is the half-life of A? What will be the pressure, initially 33.0 kPa at (a) 50 s, (b) 20 min, (c) 20 h after initiation of the reaction?
The rate constant for the first-order decomposition of N2O5 by the reaction 2 N2O5 (g) ...
The rate constant for the first-order decomposition of N2O5 by the reaction 2 N2O5 (g)  4 NO2(g) + O2(g) is k, = 3.38 x 10-5 s -1 at 25 C. What is the half-life of N2O5? What will be the partial pressure, initially 500 Torr, at ( a) 50 s; (b) 20 min, (c) 2 hr after initiation of the reaction?
The decomposition of XY is second order in XY and has a rate constant of 7.08×10−3...
The decomposition of XY is second order in XY and has a rate constant of 7.08×10−3 M−1⋅s−1 at a certain temperature. Part E If the initial concentration of XY is 0.050 M, what is the concentration of XY after 55.0 s ? Express your answer using two significant figures. Part F If the initial concentration of XY is 0.050 M, what is the concentration of XY after 550 s ? Express your answer using two significant figures.
The decomposition of N2O to N2 and O2 is a first-order reaction. At 730°C, the rate...
The decomposition of N2O to N2 and O2 is a first-order reaction. At 730°C, the rate constant of the reaction is 1.94 × 10-4 min-1. If the initial pressure of N2O is 4.70 atm at 730°C, calculate the total gas pressure after one half-life. Assume that the volume remains constant.
The decomposition of N2O to N2 and O2 is a first-order reaction. At 730°C, the rate...
The decomposition of N2O to N2 and O2 is a first-order reaction. At 730°C, the rate constant of the reaction is 1.94 × 10-4 min-1. If the initial pressure of N2O is 4.70 atm at 730°C, calculate the total gas pressure after one half-life. Assume that the volume remains constant.
1)A second order reaction has a rate constant of 3.7 M-1min-1. if the initial concentration of...
1)A second order reaction has a rate constant of 3.7 M-1min-1. if the initial concentration of the reactant is 0.0100M, what is the concentration remaining after 15 min? a) .0099M b) .0056M c) .0025M d) .0064M 2) the rate constant for the first order decomposition of A at 500 degrees Celsius is 9.2 x 10 to the negative 3rd powers s-1. How long will it take for 90.8 % of a 0.500M sample of A to decompose a) 2.5 x...
1.) 2A → B + C The above reaction is run and found to follow second...
1.) 2A → B + C The above reaction is run and found to follow second order kinetics with a rate constant of 1.30 x 10-3 M-1sec-1. If the initial concentration of A is 1.33 M, what is the concentration after 164 seconds? 2.) 2A → B + C Two trials of the above reaction are run with the same initial concentration of A. The first trial is performed at 25oC and the second at 35oC. If the rate constant...