Advertisements
Advertisements
Question
A first order reaction has a rate constant 1.15 × 10−3 s−1. How long will 5 g of this reactant take to reduce to 3 g?
Advertisements
Solution
For first order reaction,
a = 5 g; (a – x) = 3 g; k = 1.15 × 10−3 s−1
t = `2.303/"k" log "a"/(("a" - "x"))`
= `2.303/(1.15 xx 10^-3 "s"^-1) log (5 "g")/(3 "g")`
= `2.303/(1.15 xx 10^-3 "s"^-1) (log 5 - log 3)`
= `2.303/(1.15 xx 10^-3 "s"^-1) (0.6990 - 0.4771)`
= `2.303/(1.15 xx 10^-3 "s"^-1) xx 0.2219`
= 444 S
APPEARS IN
RELATED QUESTIONS
In a pseudo first order hydrolysis of ester in water, the following results were obtained:
| t/s | 0 | 30 | 60 | 90 |
| [A]/mol L−1 | 0.55 | 0.31 | 0.17 | 0.085 |
Calculate the average rate of reaction between the time interval 30 to 60 seconds.
The rate constant for a first order reaction is 60 s−1. How much time will it take to reduce the initial concentration of the reactant to its `1/16`th value?
Which of the following graphs is correct for a first order reaction?
With the help of an example explain what is meant by pseudo first order reaction.
The rate constant of a first order reaction is 6.9 × 10–3s–1. How much time will it take to reduce the initial concentration to its 1/8th value?
First order reaction is 50% complete in 1.26 × 1014s. How much time could it take for 100% completion?
The reaction X → product
Follow first order of kinetics. In 40 minutes the concentration of 'X' changes from 0.1 m to 0.025. M. The rate of reaction when concentration of X is 0.01 m is.
Time required to decompose SO2Cl2 to half of its initial concentration is 60 minutes. If the de-composite is a first order reaction, calculated the rate constant of the reaction-
Gaseous cyclobutene isomerizes to butadiene in a first order process which has a 'k' value of 3.3 × 10−4 s−1 at 153°C. The time in minutes it takes for the isomerization to proceed 40% to completion at this temperature is ______. (Rounded-off to the nearest integer)
The decomposition of formic acid on gold surface follows first-order kinetics. If the rate constant at 300 K is 1.0 × 10−3 s−1 and the activation energy Ea = 11.488 kJ mol−1, the rate constant at 200 K is ______ × 10−5 s−1. (Round off to the Nearest Integer)
(Given R = 8.314 J mol−1 K−1)
A definite volume of H2O2 undergoing spontaneous decomposition required 22.8 c.c. of standard permanganate solution for titration. After 10 and 20 minutes respectively the volumes of permanganate required were 13.8 and 8.25 c.c. The time required for the decomposition to be half completed is ______ min.
For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ______. (Integer answer)
Radioactive decay follows first-order kinetics. The initial amount of two radioactive elements X and Y is 1 gm each. What will be the ratio of X and Y after two days if their half-lives are 12 hours and 16 hours respectively?
How will you represent first order reactions graphically?
What is the rate constant?
Define first-order reaction.
Write the equation for integrated rate law for a first order reaction.
