Welcome to Chem Zipper.com......

Search This Blog

Monday, May 10, 2021

0.5 faraday of electricity was passed to deposit all the copper present in 500 ml of CuSO4 solution. What was the Molarity of this solution?

 

Related Questions:

(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).

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:

(1) The conductivity of 0.0011028 mol per liter acetic acid is 4.95 × 10–5 S per cm. Calculate its dissociation constant if ^°m for acetic acid is 390.5 S cm2 per mol–1 .


What current strength ampere will be require to liberate 10 gm chlorine from sodium chloride solution in one hour?

 

Related Questions:

(1) The conductivity of 0.0011028 mol per liter acetic acid is 4.95 × 10–5 S per cm. Calculate its dissociation constant if ^°m for acetic acid is 390.5 S cm2 per mol–1 .