हिंदी

Define the Following Terms: Half-life Period of Reaction (T1/2). - Chemistry

Advertisements
Advertisements

प्रश्न

Define the following terms:

Half-life period of reaction (t1/2).

Advertisements

उत्तर

 Half-life period of a reaction
Half-life period of a reaction is the time taken for half of the reaction to be completed. In other words, the time in which the concentration of a reactant is reduced to half of its original value is called half-life period of the reaction.
For  zero-order reaction,
For first-order reaction,
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
2013-2014 (March) Delhi Set 2

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

For a reaction : 

(i) Write the order and molecularity of this reaction.

(ii) Write the unit of k.


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)


The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y?


In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below:

A/mol L−1 0.20 0.20 0.40
B/mol L−1 0.30 0.10 0.05
r0/mol L−1 s−1 5.07 × 10−5 5.07 × 10−5 1.43 × 10−4

What is the order of the reaction with respect to A and B?


Define the following term:

Pseudo first-order reaction


Molecularity of a 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 reaction 1/2 A ⇒ 2B, rate of disappearance of A is related 't o the appearance of B by the expression:


For reaction 2A + B → BC + D which of the following does not Express the reaction rates


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.
When a sequence of elementary reactions gives us the products, the reaction is called complex reaction. Molecularity and order of an elementary reaction are same. Zero-order reactions are relatively uncommon but they occur under special conditions. All natural and artificial radioactive decay of unstable nuclei takes place by first-order kinetics.

  1. What is the effect of temperature on the rate constant of a reason?    [1]
  2. 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]
  3. How order and molecularity are different for complex reactions?    [1]
  4. 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]

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×