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Monday, May 10, 2021
Ag is electrodeposited on a vessel of total surface area 800 cm2 by passing current of 0.2 A for 3 hrs. Calculate thickness of Ag deposited. (Density Ag = 9.67 g/ml).
(1) A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).
In Arrhenius equation for a certain reaction, the value of A and Ea (activation energy) are 4x 10^13 sec^-1 and 98.6 kJ mole^-1 respectively. At what temperature, the reaction will have specific rate constant 1.1x 10^-3 sec^-1.
Arrhenius equation:
The temperature
dependence of rate of a chemical reaction can be accurately explained by
Arrhenius equation. It was first proposed by Dutch chemist J.H.
Vant’s Hoff but Swedish chemist Arrhenius
provides its physical justification and interpretation.
Where
K=
Rate constant
A= Arrhenius constant or frequency
factor or pre exponential factor
R= Universal gas constant =25/3 joule
per mole per second
Ea= Activation
Energy
T= temperature
-Ea/RT= Boltzmann factor or fraction of molecule having equal or greater
than Activation energy or fraction of molecule that have
kinetic energy greater than activation energy.
Related Questions:
(1) What is Arrhenius equation ?
(2) what happen when activation energy of a chemical reaction becomes equal to RT?
(3) What is the activation energy and how to different from threshold energy ?
(4) In Arrhenius equation for a certain reaction, the value of A and Ea (activation energy) are 4 × 10^13 sec–1 and 98.6 kJ mol–1 respectively. At what temperature, the reaction will have specific rate constant 1.1 × 10^–3 sec–1?
(5) The energy of activation for a reaction is 100 kJ mol–1. Presence of a catalyst lowers the energy of activation by 75%.What will be effect on rate of reaction at 20ºC, other things being equal?
(6) 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 of the drug in months. What is the half life of the product?
(7) A first order reaction is 20 % completed in 10 minutes. Calculate the time taken for the reaction to go to 80 % completion.
(8) The rate of a reaction triple when temperature changes from 20”C to 50”C. Calculate energy of activation for the reaction (R = 8.314 JK^1 mol^1).
Sunday, May 9, 2021
A current of 2.68 ampere is passed for one hour through an aqueous solution of copper sulphate using copper electrodes. Calculate the change in the mass cathode and that of anode. ( atomic mass of copper is 63.5 u).
Related Questions:
What current strength ampere will be require to liberate 10 gm chlorine from sodium chloride solution in one hour?
Related Questions:
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