Hardayal Public School Holiday Assignment of ... - Educomp Online

long did the current flow? What mass of copper and of zinc were deposited? Atmasses of Ag, Cu, Zn are 108 u, 63.5 u and 65 u respectively.Chapter – 4 Chemical Kinetics1. Give the units of rate constant of 1st order, 2nd order, 3rd order and nth orderreaction.2. What is a first order reaction? Give two examples.3. Derive expression for the rate constant of the first order reaction. Show that log[A] is a linear function of time.4. How can the plot of log [A] and t be used for the calculation of rate constant forthe first order?5. What would be probable plot of conc. vs. time for zero order reaction?6. What is meant by half life period?7. The rate of a reaction is given by equationRate = k[A]2[B]What are the units of the rate and rate constant for this reaction?8. Explain the following :(i) activation energy (ii) threshold energy(iii) activated complex9. The decomposition of a compound is found to follow a first-order rate law. If ittakes 15 minutes for 20 percent of original material to react, calculate (i) thespecific rate constant, (ii) the time at which 10 percent of the original materialremains unreacted, (iii) the time it takes for the next 20 percent of the reactantleft to react first 15 minutes.10. Find the two-third life, t 2/3 , of a first order reaction in which k = 5.4 × 10 –14 s –1 .Chapter – 5 Surface Chemistry1. What is the effect of temperature on adsorption?2. What is heterocatalysis?3. Give one example of a peptizing agent.4. Write a short note on adsorption. How does it differ from absorption?5. What is adsorption? Write any two features that distinguish physisorption fromchemisorptions.6. On what factors does adsorption of gases on solids depend?7. What are isotherms and isobars? What is the difference between isotherms ofphysisorption and chemisorptions?8. What do you understand by the terms(i) Catalyst (ii) Promoter (iii) Poison.Give one example of each.9. Give two chemical methods for the preparation of colloids.10. Give two physical methods for the preparation of colloids.11. Write brief note on :(i) Coagulation (ii) Gold number (iii) Hardy-Schulze rule12. Explain the following terms :(i) Lyophobic sols (ii) Gold number (iii) Peptisation