(1) All questions are compulsory. (2) Figures to the right indicate full marks. (3) Assume suitable data, if necessary. MARKS 20
3 Hours/100 Marks Instructions :
1. Attempt any ten of the following : a) Why is an atom electrically neutral ? b) Differentiate between isotopes and isobars. c) Define conductor and nonconductor. d) State Faraday’s second law of electrolysis. e) Define cell. Give its classification. f) Explain the terms mineral and ore. g) Define alloys with suitable example. h) What is nickel silver ? Write its composition. i) Give composition of glass-wool. j) Name the types of plastics with examples of each. k) Define COD of sewage. l) Define Air-pollution. Give its magnitude.
2. Attempt any four of the following : 16 a) Give the comparison of electron, proton and neutron w.r.to their symbol, change, mass and location within an atom. b) Give four points of distinction between orbit and orbital. c) Write orbital electronic configuration of the following elements 24 39 20 N14 , Mg 12 , K 19 , Ne10 7
d) Describe the formation of NaCl molecule with diagram and name the type of bonding. e) Explain electrovalency and covalency with example. f) State and explain Faraday’s first law of electrolysis. P.T.O.
*12002* MARKS 3. Attempt any four of the following : 16 a) Draw diagram and explain the construction working of lead-acid storage cell. b) A given quantity of electricity is passed through two cells containing copper sulphate and silver nitrate respectively. If 0.99 gms of silver and 0.29 gms of copper are deposited, find equivalent weight of silver when that of copper is 31.6. c) Explain the mechanism of electrolysis of fused sodium-chloride by using carbon electrodes. d) Why copper is electro-refined ? Describe the process of electro-refining of copper. e) Explain construction working and application of dry-cell. f) Define metallurgy. Outline the general principle of metallurgy.