Advertisements
Advertisements
प्रश्न
Consider a first order gas phase decomposition reaction given below :
\[\ce{A(g) -> B(g) + C(g)}\]
The initial pressure of the system before decomposition of A was pi. After lapse of time ‘t’, total pressure of the system increased by x units and became ‘pt’ The rate constant k for the reaction is given as ______.
पर्याय
`k = 2.303/t log p_i/(p_i - x)`
`k = 2.303/t log p_i/(2p_i - p_t)`
`k = 2.303/t log p_i/(2p_i + p_t)`
`k = 2.303/t log p_i/(p_i + x)`
Advertisements
उत्तर
The initial pressure of the system before decomposition of A was pi. After lapse of time ‘t’, total pressure of the system increased by x units and became ‘pt’ The rate constant k for the reaction is given as `k = 2.303/t log p_i/(2p_i - p_t)`.
Explanation:
Consider a first order gas phase decomposition reaction:
\[\ce{A_{(g)} -> B_{(g)} + C_{(g)}}\]
The initial pressure of the system before decomposition of A was Pi.
After lapse of time (t), total pressure of the system increased by x units and became 'Pt'.
In other words, the pressure of A decreased by x atom.
\[\ce{A_{(g)} -> B_{(g)} + C_{(g)}}\]
Initial pressure: Pi atm
Pressure after time t: (Pi – x) atm x atm x atm
Pt = (Pi – x) + x + x = Pi + x atm
x = Pt – Pi
PA = Pressure of A after time t = Pi - x = Pi - (Pi - Pi) = 2Pi - Pt
`k = 2.303/t log (["A"]_0)/(["A"])`
= `k = 2.303/t log p_i/(2p_i - p_t)`
APPEARS IN
संबंधित प्रश्न
In a first order reaction x → y, 40% of the given sample of compound remains unreacted in 45 minutes. Calculate rate constant of the reaction.
Write molecularity of the following reaction:
2NO(g)+O2(g)→2NO2(g)
For a reaction A + B ⟶ P, the rate is given by
Rate = k [A] [B]2
What is the overall order of reaction if A is present in large excess?
For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained :
| t/s | 0 | 30 | 60 |
| [CH3COOCH3] / mol L–1 | 0.60 | 0.30 | 0.15 |
(i) Show that it follows pseudo first order reaction, as the concentration of water remains constant.
(ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds.
(Given log 2 = 0.3010, log 4 = 0.6021)
Mention the factors that affect the rate of a chemical reaction.
The value of rate constant of a pseudo first order reaction ______.
Consider the reaction A ⇌ B. The concentration of both the reactants and the products varies exponentially with time. Which of the following figures correctly describes the change in concentration of reactants and products with time?
For a complex reaction:
(i) order of overall reaction is same as molecularity of the slowest step.
(ii) order of overall reaction is less than the molecularity of the slowest step.
(iii) order of overall reaction is greater than molecularity of the slowest step.
(iv) molecularity of the slowest step is never zero or non interger.
The role of a catalyst is to change
For a reaction A + B → products, the rate law is given by: r = `K[A]^(1/2)`. What is the order of reaction?
The rate constant for the reaction \[\ce{2H2O5 -> 4NO2 + O2}\] is 30 × 10–5 sec–1. if the rate is 204 × 10–5 mol L–1 S–1, then the concentration of N2O5 (in mol–1) is-
The half-life period of a. substance in a certain enzyme catalysed reaction is 138 s. The time required for the concentration of the substance to fall from 1.28 mol–1 to 0.04 mg L–1 is
At concentration of 0.1 and 0.2 mol L–1 the rates of deem position of a compound were found to be 0.18 and 0.72 mol L–1 m–1. What is the order of the reaction?
For the reaction, \[\ce{A +2B → AB2}\], the order w.r.t. reactant A is 2 and w.r.t. reactant B. What will be change in rate of reaction if the concentration of A is doubled and B is halved?
Read the following passage and answer the questions that follow:
|
The rate of reaction is concerned with decrease in the concentration of reactants or increase in the concentration of products per unit of time. It can be expressed as instantaneous rate at a particular instant of time and average rate over a large interval of time. A number of factors such as temperature, concentration of reactants, catalyst affect the rate of reaction. Mathematical representation of rate of a reaction is given by rate law: Rate = k[A]x [B]y x and y indicate how sensitive the rate is to change in concentration of A and B. Sum of x + y gives the overall order of a reaction. |
- What is the effect of temperature on the rate constant of a reason? [1]
- For a reaction \[\ce{A + B → Product}\], the rate law is given by, Rate = k[A]2 [B]1/2. What is the order of the reaction? [1]
- How order and molecularity are different for complex reactions? [1]
- A first-order reaction has a rate constant 2 × 10–3 s–1. How long will 6 g of this reactant take to reduce to 2 g? [2]
OR
The half-life for radioactive decay of 14C is 6930 years. An archaeological artifact containing wood had only 75% of the 14C found in a living tree. Find the age of the sample.
[log 4 = 0.6021, log 3 = 0.4771, log 2 = 0.3010, log 10 = 1] [2]
A drop of solution (volume 0.05 ml) contains 3.0 × 10-6 mole of H+. If the rate constant of disappearance of H+ is 1.0 × 107 mole l-1s-1. It would take for H+ in drop to disappear in ______ × 10-9s.
For a chemical reaction starting with some initial concentration of reactant At as a function of time (t) is given by the equation,
`1/("A"_"t"^4) = 2 + 1.5 xx 10^-3` t
The rate of disappearance of [A] is ____ × 10-2 M/sec when [A] = 2 M.
[Given: [At] in M and t in sec.]
[Express your answer in terms of 10-2 M /s]
[Round off your answer if required]
Higher yield of NO in \[\ce{N2(g) + O2 <=> 2NO(g)}\] can be obtained at:
[ΔH of the reaction = +180.7 kJ mol−1]
- higher temperature
- lower temperature
- higher concentration of N2
- higher concentration of O2
Choose the correct answer from the options given below:
