State how -
(i) a higher ratio of the reactant air
exothermicity of the catalytic reaction
(iii) use of low temp . In the conversion of NO to `NO_(2)-` affects each related step in Ostwald's process.

For the reaction 5Br^(-)(aq)+BrO_(3)^(-)(aq)+6H^(+)(aq)rarr 3Br_(2)(aq)+3H_(2)O(l) the reate expression was found to be -(d[BrO^(3-)])/(dt)=k[Br^(-)][H^(+)]^(2)[BrO_(3)^(-)] Which of the following statements is /are correct? I. Doubling the intial concentration of all the reactants will increase the reaction rate by a factor of 8. II. Unit of rate constant of the reaction in a buffer solution is "min"^(-1) III. Doubling the concentration of all the reactants at the same time will increase the reaction rate by a factor of 16 IV. rate of conversion of BrO_(3)^(-) and rate of disappearance of Br^(-) are the same

The reaction 2AX(g)+2B_(2)(g)rarr A_(2)(g)+2B_(2)X(g) has been studied kinetically and on the baiss of the rate law following mechanism has been proposed. I. 2A X hArr A_(2)X_(2) " " ("fast and reverse") II. A_(2)X_(2)+B_(2)rarrA_(2)X+B_(2)X III. A_(2)X+B_(2)rarrA_(2)+B_(2)X where all the reaction intermediates are gases under ordinary condition. form the above mechanism in which the steps (elementary) differ conisderably in their rates, the rate law is derived uisng the principle that the slowest step is the rate-determining step (RDS) and the rate of any step varies as the Product of the molar concentrations of each reacting speacting species raised to the power equal to their respective stoichiometric coefficients (law of mass action). If a reacting species is solid or pure liquid, its active mass, i.e., molar concentration is taken to be unity, the standard state. In qrder to find out the final rate law of the reaction, the concentration of any intermediate appearing in the rate law of the RDS is substituted in terms of the concentration of the reactant(s) by means of the law of mass action applied on equilibrium step. How many times the rate of formation of A_(2) will increase if concentrations of AX is doubled and that of B_(2) is increased theee fold?

The reaction 2AX(g)+2B_(2)(g)rarr A_(2)(g)+2B_(2)X(g) has been studied kinetically and on the baiss of the rate law following mechanism has been proposed. I. 2A X hArr A_(2)X_(2) " " ("fast and reverse") II. A_(2)X_(2)+B_(2)rarrA_(2)X+B_(2)X III. A_(2)X+B_(2)rarrA_(2)+B_(2)X where all the reaction intermediates are gases under ordinary condition. form the above mechanism in which the steps (elementary) differ conisderably in their rates, the rate law is derived uisng the principle that the slowest step is the rate-determining step (RDS) and the rate of any step varies as the Product of the molar concentrations of each reacting speacting species raised to the power equal to their respective stoichiometric coefficients (law of mass action). If a reacting species is solid or pure liquid, its active mass, i.e., molar concentration is taken to be unity, the standard state. In qrder to find out the final rate law of the reaction, the concentration of any intermediate appearing in the rate law of the RDS is substituted in terms of the concentration of the reactant(s) by means of the law of mass action applied on equilibrium step. Let the equilibrium constant of Step I be 2xx10^(-3) mol^(-1) L and the rate constants for the formation of A_(2)X and A_(2) in Step II and III are 3.0xx10^(-2) mol^(-1) L min^(-1) and 1xx10^(3) mol^(-1) L min^(-1) (all data at 25^(@)C) , then what is the overall rate constant (mol^(-2) L^(2) min^(-1)) of the consumption of B_(2) ?

The order of reaction is an experimentally determined quanity. It may be zero, poistive, negative, or fractional. The kinetic equation of nth order reaction is k xx t = (1)/((n-1))[(1)/((a-x)^(n-1)) - (1)/(a^(n-1))] …(i) Half life of nth order reaction depends on the initial concentration according to the following relation: t_(1//2) prop (1)/(a^(n-1)) ...(ii) The unit of the rate constant varies with the order but general relation for the unit of nth order reaction is Units of k = [(1)/(Conc)]^(n-1) xx "Time"^(-1) ...(iii) The differential rate law for nth order reaction may be given as: (dx)/(dt) = k[A]^(n) ...(iv) where A denotes the reactant. In a chemical reaction A rarr B , it is found that the rate of the reaction doubles when the concentration of A is increased four times. The order of the reaction with respect to A is:

Choose the correct option the code regarding roasting process. (I) It is the process of heating the ore in air in a reverberatory furnace to obtain the oxide. (II) It is an exothermic process. (III) It is used for the concentration of sulphide ore. (Iv) It removes easily oxidisable volatile impurities present in the concentrated ore.

In the adjacent diagram, AO is a ray of light incident on a rectangular glass slab. (a) Complete the path of the ray till it emerges out of the slab. (b) In the diagram, mark the angle of incidence (i) and the angle of refraction (r) at the first interface. how is the refractive index of glass related to the angles i and r ? (c) Mark angle of emergence by the letter e. how are the angles i and e related ? (d) Which two rays are parallel to each other ? Name them (e) Indicate in the diagram the lateral displacement between the emergent ray and the incident ray. state one factor that affects the lateral displacement.

Draw the diagram a of galvanic cell involving following reactions : Zn+Cu^(+) to Zn^(2+) +Cu and answer the following questions: (i) Label the cathode and anode (ii) How does the e.m.f. of the cell changes with the decrease in the concentration of Cu^(2+) ions ? (iii) What is the function of salt bridge in it? (iv) Name the salt to be used in salt bridge. (v) Write the reactions occurring at each electrode. (vi) In which direction the electrons would flow in the external circuit? (vii) How electrical neutrality is maintained in both the half cells?

For a sponaneous reaction, the free energy change must be negative, Delta G=Delta H-T Delta S, Delta H is the enthalpy change during the reaction. T is the absolute temperature, and Delta S is the change in entropy during the reaction. Consider a reaction such as the formation of an oxide M+O_(2) to MO Dioxygen is used up in the course of this reaction. Gases have a more random structure (less ordered) than liquid or solids. Consequently gases have a higher entropy than liquids and solids. In this reaction S (entropy or randomness) decreases, hence Delta S is negative. Thus, if the temperature is raised then T Delta S becomes more negative,Since, TDelta S is substracted in the equation, then Delta G becomes less negative. Thus, the free energy change increases with the increase in temperature. The free energy changes that occur when one mole of common reactant (in this case dioxygen) is used may be plotted graphically aginst temperature for a number of reactions of metals to their oxides. The following plot is called an Ellingham diagram for metal oxide. Understanding of Ellingham diagram is extremely important for the efficient extraction of metals. For the conversion of Ca(s) to Ca(s) which of the following represent the Delta G vs. T ?

Chemical reactions are invariably associated with the transfer of energy either in the form of hear or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms Delta T , s= Specific heat = c Delta T = Heat capacity. Heat of reaction at constant pressure is measured using simple or water calorimeter. Q_(v)= Delta U = Internal energy change, Q_(P) = DeltaH, Q_(P) = Q_(V) + P Delta V and DeltaH = Delta U+ Delta nRT . The amount of energy released during a chemical change depends on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchoff's equation: (DeltaH_(2) - DeltaH_(1))/(T_(2)-T_(1))= Delta C_(P) (At constant pressure), (DeltaU_(2) - DeltaU_(1))/(T_(2)-T_(1)) = DeltaC_(V) (At constant volume) The specific heat of I_(2) in vapoour and solid state are 0.031 and 0.055 cal/g respectively. The heat of sublimation of iodine at 200^(@)C is 6.096 kcal mol^(-1) . The heat of sublimation of iodine at 250^(0)C will be

(a) Complete the following chemical equations for reactions : (i) MnO_(4(aq))^(-) + S_(2)O_(3(aq))^(2-) + H_(2)O_((l)) to (ii) Cr_(2)O_(7 (aq))^(2-) + H_(2)S_((g)) + H_((aq))^(+) to (b) Give an explanation for each of the following observations : (i) The gradual decrease in size (actinoid contraction) from element to element is greater among the actinoids than that among the lanthanoids (lanthanoid contraction.) (ii) The greatest number of oxidation states are exhibited by the members in the middle of a transition series. (iii) With the same d-orbitals configuration (d^(4)) Cr^(2+) ion is a reducing agent but Mn^(3+) ion is an oxidising agent .