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Activation energy for decomposition of H_{2}O_{2} is 76 kJ/mol at 298K and the decomposition is very slow. When a little iodide is added, the activation energy decreases to 57kJ/mol. Hence, rate coefficient increases by a factor of
The rate of radioactive disintegration ..........with time:
For opposing reaction, A + B ↔ C + D, Ea = 100 kJ/mol and A = 1010 M1s1. The equilibrium concentration of A, B, C, D are 1, 2, 5, 4 M resp., at 700K. The values of k1 and k1 at this temp are
If 0.001M of a substance quenches the efficiency of fluorescence by 20%, the value of SternVolmer constant in M^{1} is
Decomposition of ammonia on tungsten at 850^{o}C has a rate constant value of 0.10 Torr sec^{1}. If the initial pressure of ammonia is 100 Torr, the pressure of ammonia at t = 200 sec is
The value of the rate constant for the gas phase reaction, 2NO_{2} + F_{2} → 2NO_{2}F is 38 dm^{3} mol^{–1} s^{–1} at 300 K. The order of the reaction is:
A reaction follows second order rate law,
The specific rate constant of decomposition of a compound is represented by
The activation energy of decomposition for this compound at 300 K is:
The fluorescence life time of a molecule in solution is 10 ns. If the fluorescence quantum yield is 0.1, the rate constant of fluorescence decay is:
For the reaction shown below,
The value of k_{1} is 1 × 10^{–4} s^{–1}. If the reaction starts from X, the ratio of the concentrations of Y and Z at any given time during the course of the reaction is found to be The value of k_{2} is:
For an adsorbantadsorbate system obeying the Langmuir adsorption isotherm, K = 0.48 bar^{1} and P = 0.16 bar^{1}. At what pressure will 50% of the surface be covered?
The reaction, 2NO(g) + O_{2}(g) → 2NO_{2}(O) proceeds via the following steps:
The rate of this reaction is equal to
The decomposition of N_{2}O_{5} according to following reaction is first order
2 N_{2}O_{5} → 4 NO_{2}(g) + O_{2} (g). After 30 minutes from the start of decomposition in a closed vessel the total pressure developed is found to be 250 mm of Hg and on complete decomposition the total pressure is 500 mm of Hg. Calculate rate constant of the reaction.
1 g of ^{90}Sr gets converted to 0.953 g after 2 yr. The halflife of 90Sr, and the amount of ^{90}Sr remaining after 5 yr are:
A graph is plotted between log10K and 1/T in which straight line BC has no slope and tan(ᴓ) = 1/2.303 and intercept on yaxis is 5. What is activation energy?
In a reaction, A + B → Product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants (Aand B) are doubled, rate law for the reaction can be written as
when the rate of the reaction is equal to the rate constant, the order of the reaction is
The inversion of cane sugar proceeds with halflife of 500 minutes at pH 5 for any concentration of sugar. However if pH = 6, the halflife changes to 50 minute. The rate law expression for the sugar inversion can be written as:
The reaction, A(g) + 2B(g) → C(g) + D(g) is an elementary process. In an experiment, the initial partial pressure of A and B are P_{A }= 0.60 and P_{B} = 0.80 atm. When P_{C} = 0.2 atm the rate of reaction relative to the initial rate is:
For an enzyme catalyzed reaction, a LineweaverBurk plot gave the slope value = 40 s and intercept = 4 (mmoldm^{3}s^{1})^{1}. If initial concentration of enzyme is 2.5× 10^{9} moldm^{3}, catalytic efficiency is 10^{x}. Calculate the value of ‘x’.
At 273 K, N_{2} is adsorbed on mica surface. A plot of 1/V vs 1/P (V in m^{3} and P in Torr) gives a straight line with slope equal to 2.0 × 10^{–5} torr m^{–3} and an intercept V_{m} equal to 4 × 10^{–8} m^{3}. The adsorption coefficient and number of molecules of N_{2} forming monolayer, resp., are:
Physiosorbed particles undergo desorption at 27^{0}C with an activation energy of 16.628 kJ/mol. Assuming first order process and a frequency factor of 10^{12} Hz, the average residence time (in sec) of particles on the surface is
A monoatomic gas, X absorbed on a surface, Langmuir, A plot of the fraction of surface coverage, q against the concentration of the gas [X], for very low concentration of the gas, is described by the equation:
Which of the following transformations is not correct?
Which ones of the following reactions are artificial radioactive decay?
A, B, C and D elements form compounds AC, A_{2}D and BD. If AC and A_{2}D are radioactive and BD is not radioactive compound, find the following radioactive compounds
(I) A_{2} (II) A_{2}C (III) C_{2}D (IV) BC
A substance absorbs 2.0 x 10^{16} quanta or radiations per second and 0.002 mole of it reacts in 1200 seconds. What is the quantum yield or the reaction (N = 6.02 x 10^{23})?
Which regions of the light radiations of the visible ultraviolet lying between – wavelength are chiefly concerned in bringing about photochemical reactions?
A closed vessel with rigid walls contain 1 mol of _{92}U^{238} and 1 mol of air at 298K. Considering complete decay of _{92}U^{238} to _{82}U^{206}, the ratio of the final pressure to the initial pressure of the system at 298K is____?
The periodic table consists of 18 groups. An isotope of copper, on bombardment with protons, undergoes a nuclear reaction yielding element X as shown below. To which group, element X belongs in periodic table? _{29}Cu^{63} + _{1}H^{1} → X + 2 _{1}H^{1} + α + 6 _{0}n^{1}
Considering the following parameters with reference to fluorescence of a solution. The correct answer for the enhancement of fluorescence with the increase in these parameters is/are
Which one of the following nuclear reaction is/are correct?
Which among the following is/are correct about Isodiaphers?
Which of the following is secondary effect?
Which of the following statements is correct?
Which of the following is/are true about Chemisorption?
Which of the following statements are correct?
Which of the following are the reactions in which molecules absorbing light do not themselves react but induce other molecules to react?
What are the appropriate reasons for deviations from Beer’s law among following?
Which ones of the following statements are true for halflife of radioactive matters?
It was found that cane sugar solution in water was hydrolyzed to the extent 25 per cent in one hour. Calculate the time (in hours) that will be taken for the sugar to get hydrolyzed to the extent of 50%, assuming that the reaction is of the first order: [rounded up to first decimal place]
A drug becomes ineffective after 30% decomposition. The original concentration of a sample was 5mg/mL which becomes 4.2 mg/mL during 20 months. Assuming the decomposition of first order, calculate the expiry time (in months) of the drug in months.
The reaction is first order in both the directions. The forward and reverse rate constants are 4.2 × 10^{–4}s^{–1} and 1.04 × 10^{–3} s^{–1}, respectively. The relaxation time for this reaction, in seconds, in a temperature jump experiment is…………….? [rounded up to two decimal place]
A first order reaction is 20% completed in 10 minutes. Calculate the time (in minutes) taken for the reaction to go to 80% completion: [rounded up to two decimal places]
The rate of a reaction triple when temperature changes from 20°C to 50°C. Calculate energy (J/mol) of activation for the reaction (R = 8.314 JK^{–1} mol^{–1}). [rounded up to first decimal place]
^{210}Bi undergoes β^{–} decay to 1/8 of its initial amount in 15 days. The time required for its decay to 1/4 of its initial amount is……… days:
The halflife of a radioactive element is 30 min. The time interval between the stages of 33.3% and 67.7% decay will be (in min): [rounded up to first decimal place]
A 0.1 M solution of compound A shows 50% transmittance when a cell of 1 cm width is used at λ_{1} nm. Another 0.1 M solution of compound B gives the optical density value of 0.1761 using 1cm cell at λ_{1} nm. What will be the transmittance of a solution that is simultaneously 0.1 M in A and 0.1 M in B using the same cell and at the same wave length? [log 1.301; log 1.4771; log 50 = 1.699]. (rounded up to two decimal places)
Halflife for a third order reaction 3C → products, where C_{o} is initial concentration of C will be 1/[zKC_{o}^{2}]. The value of ‘z’ is? [rounded up to two decimal places]
For nondissociative Langmuir type adsorption of a gas on solid surface at a particular temp, the fraction of surface coverage is 0.6 at 30 bar. The Langmuir isotherm constant (in bar^{1}) at this temp is? [rounded up to two decimal places]
In Arrhenius equation for a certain reactions, the value of A and E_{a} (Activation energy) are 4 × 10^{13} sec^{–1} and 98.6 kJ/mol respectively. At what temperature (K), the reaction will have specific rate constant 1.1 × 10^{–3} sec^{–1}? [rounded up to first decimal place]
At 407 K the rate constant of a chemical reaction is 9.5 × 10^{–5}s^{–1} and at 420 K, the rate constant is 1.9 × 10^{–4}s^{–1}. Calculate the frequency factor of the reaction: [rounded up to two decimal places]
The decomposition of Cl_{2}O_{7} at 400 K in the gas phase to Cl_{2} and O_{2} is of I^{st} order. After 55 sec at 400 K, the pressure of Cl_{2}O_{7} falls from 0.062 to 0.044 atm. Calculate pressure (atm) of Cl_{2}O_{7} after 100 seconds: [rounded up to three decimal places]
A sample of _{53}I^{131}, as iodide ion, was administered to a patient in a carrier consisting of 0.10 mg of stable iodide ion. After 4.00 days, 67.7% of the initial radioactivity was detected in the thyroid gland of the patient. What mass (in mg) of the stable iodide ion had migrated to the thyroid gland?
Given T_{1/2} I^{131} = 8 days. [rounded up to three decimal places]
For the reaction,
at 900 K, the following data are obtained:
Find the value of rate constant (in atm^{–2} min^{–1}). [rounded up to two decimal places]
Two substances A and B are present such that [A_{0}] = 4[B_{0}] and halflife of A is 6 minute and that of B is 15 minute. If they start decaying at the same time following first order kinetics, how much time (min) later will the concentration of both of them would be same?
For the first order reaction the initial pressure is P_{A} = 90 mm Hg, the pressure after 10 minutes is found to be 180 mm Hg. The rate constant (in sec^{1})of the reaction is
Q × 10^{–3}: Therefore, Q is __? [rounded up to two decimal places]
Radioactive decay is a first order process. Radioactive carbon wood sample decays with a halflife of 5770 years. What fraction would remain after 11540 years? [rounded up to three decimal places]
V_{max} and K_{M} for an enzyme catalyzed reactions are 2.0 × 10^{–3} Ms^{1} and 1.0 × 10^{–6} M resp., The rate of reaction when substrate concentration is 1.0 × 10^{–6} M is? [up to three decimal places]
First order rate constant for unimolecular gas phase reaction A → products that follows Lindemann mechanism is 2 s^{1} at P_{A} = 1 atm and 4 s^{1} at P_{A} = 2 atm. The rate constant (in atm^{1}s^{1}) for activation step is?
2 docs25 tests

2 docs25 tests
