Advertisements
Advertisements
प्रश्न
How do nature of the reactant influence rate of reaction?
उत्तर
Nature and state of the reactant: We know that a chemical reaction involves breaking of certain existing bonds of the reactant and forming new bonds which lead to the product.
The net energy involved in this process is dependent on the nature of the reactant and hence the rates are different for different reactants. Let us compare the following two reactions that we carried out in the volumetric analysis.
- Redox reaction between ferrous ammonium sulphate (FAS) and KMnO4
- Redox reaction between oxalic acid and KMnO4
The oxidation of oxalate ions by KMnO4 is relatively slow compared to the reaction between KMnO4 and Fe. In fact, heating is required for the reaction between KMnO4 and Oxalate ion and is carried out at around 60°C. The physical state of the reactant also plays an important role to influence the rate of reactions. Gas phase reactions are faster as compared to the reactions involving solid or liquid reactants.
For example, the reaction of sodium metal with iodine vapours is faster than the reaction between solid sodium and solid iodine. Let us consider another example that we carried out in the inorganic qualitative analysis of lead salts.
If we mix the aqueous solution of colorless potassium iodide with the colorless solution of lead nitrate, precipitation of yellow lead iodide takes place instantaneously, whereas if we mix the solid lead nitrate with solid potassium iodide, yellow coloration will appear slowly.
APPEARS IN
संबंधित प्रश्न
The addition of a catalyst during a chemical reaction alters which of the following quantities?
In a reversible reaction, the enthalpy change and the activation energy in the forward direction are respectively −x kJ mol−1 and y kJ mol−1. Therefore , the energy of activation in the backward direction is
What is the activation energy for a reaction if its rate doubles when the temperature is raised from 200 K to 400 K? (R = 8.314 JK−1mol−1)
If the initial concentration of the reactant is doubled, the time for half reaction is also doubled. Then the order of the reaction is ____________.
In a homogeneous reaction \[\ce{A -> B + C + D}\], the initial pressure was P0 and after time t it was P. Expression for rate constant in terms of P0, P and t will be
The correct difference between first and second order reactions is that
The rate law for a reaction of A, B and C has been found to be rate = `"k" ["A"]^2["B"] ["L"]^(3/2)`. How would the rate of reaction change when
- Concentration of [L] is quadrupled
- Concentration of both [A] and [B] are doubled
- Concentration of [A] is halved
- Concentration of [A] is reduced to `(1/3)` and concentration of [L] is quadrupled.
The rate of formation of a dimer in a second order reaction is 7.5 × 10−3 mol L−1s−1 at 0.05 mol L−1 monomer concentration. Calculate the rate constant.
For a reaction \[\ce{x + y + z -> products}\] the rate law is given by rate = `"k" ["x"]^(3/2) ["y"]^(1/2)` what is the overall order of the reaction and what is the order of the reaction with respect to z.
Benzene diazonium chloride in aqueous solution decomposes according to the equation \[\ce{C6H5N2Cl -> C6H5Cl + N2}\]. Starting with an initial concentration of 10 g L−1, the volume of N2 gas obtained at 50°C at different intervals of time was found to be as under:
| t (min): | 6 | 12 | 18 | 24 | 30 | ∞ |
| Vol. of N2 (ml) |
19.3 | 32.6 | 41.3 | 46.5 | 50.4 | 58.3 |
Show that the above reaction follows the first order kinetics. What is the value of the rate constant?
