Question

The isomerization reaction CH3NC (g) <---> CH3CN (g) obeys the first order rate law. At 500K,...

The isomerization reaction CH3NC (g) <---> CH3CN (g) obeys the first order rate law. At 500K, the concentration of CH3NC is 85% of its original value after 247s. What is the rate constant for this decomposition at 500K? At what time will the concentration of CH3NC be 25℅ of its original value?

Homework Answers

Answer #1

for the first order reaction we know that

where Ca = Concentration at any time t

Cao = intial concentration

K = rate constant

t = time

according to the problem Ca = 0.85 Cao at t=247s

therefore putting the values we get,

therefore value of K = sec-1

for the next part..

given that Ca = 0.25 Cao

therefore again using the formula

we get

therefore t= 2110.037 sec

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
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 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 following reaction is first order in N2O5 : N2O5 (g)→ NO3(g) + NO2(g) The rate...
The following reaction is first order in N2O5 : N2O5 (g)→ NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s Calculate the rate of reaction when [N2O5]=0.055M What would the rate of reaction be at the same concentration if the reaction was second order? Zero order? (Assume same numerical value for the rate constant but with correct units)
1. The rate law for the reaction is: Cl2(g) + CHCl3 (g) = HCl (g) +...
1. The rate law for the reaction is: Cl2(g) + CHCl3 (g) = HCl (g) + CCl4 (g) Is Rate = k [Cl2]^1/2 [CHCl3] What are the units for k, assuming time inow seconds and concentration in mol/L 2. What is the unit for the rate of a chemical reaction and the rate constant for a third-order rate law?
The following is known about the reaction below: Chemical reaction: 2A-->2B The order of A is...
The following is known about the reaction below: Chemical reaction: 2A-->2B The order of A is second order If you start out with 2.75 M of A, after 5 minutes you will have 2.00M From these facts, determine: a) the rate law constant, K b) the first half life c) from time 0, how long will it take to reach 25% of the original concentration of A d) what is the concentration of A after 10 minutes?
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.
Consider the following reaction: 2NO(g)+2H2(g)→N2(g)+2H2O(g) What is the reaction rate at 1000 K when the concentration...
Consider the following reaction: 2NO(g)+2H2(g)→N2(g)+2H2O(g) What is the reaction rate at 1000 K when the concentration of NO is increased to 0.11 M, while the concentration of H2 is 1.50×10−2 M? and If a solution containing 30.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives? and lastly The isomerization of methylisonitrile to acetonitrile CH3NC(g)→CH3CN(g) is first order in in CH3NC. The half-life of the reaction is 5.20 × 101 s at 545 K....
The integrated rate law allows chemists to predict the reactant concentration after a certain amount of...
The integrated rate law allows chemists to predict the reactant concentration after a certain amount of time, or the time it would take for a certain concentration to be reached. The integrated rate law for a first-order reaction is: [A]=[A]0e−kt Now say we are particularly interested in the time it would take for the concentration to become one-half of its inital value. Then we could substitute [A]02 for [A] and rearrange the equation to: t1/2=0.693k This equation caculates the time...
The integrated rate laws for zero-, first-, and second-order reaction may be arranged such that they...
The integrated rate laws for zero-, first-, and second-order reaction may be arranged such that they resemble the equation for a straight line,y=mx+b. 1.) The reactant concentration in a zero-order reaction was 6.00×10−2M after 165 s and 3.50×10−2Mafter 385 s . What is the rate constant for this reaction? 2.)What was the initial reactant concentration for the reaction described in Part A? 3.)The reactant concentration in a first-order reaction was 6.70×10−2 M after 40.0 s and 2.50×10−3Mafter 95.0 s ....
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?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT