SEMINAR ON PEDAGOGY TOPIC: Some compounds of non metals

1. SEMINAR ON PEDAGOGYTOPIC: Some compounds of non metals Submitted by Parvathy Prakash Optional subject: physical science Reg.no:

2. Introduction There are many compounds of non metals found in our earth. We all are familiar with pesticides that we use in farm. The major content of these pesticides is a compound of non metal- ammonia. The most abundant particle in atmosphere is also a non metal nitrogen. So in this chapter we are going to study about some important compounds of non metals.

3. Laboratory preparation of ammonia. Ammonia is prepared in the laboratory by heating a mixture of ammonium chloride and calcium hydroxide. In order to make ammonia moisture free, we use CaO as the drying agent. Ammonia dissolves in water. To prove this, let’ do an experiment: Collect ammonia in an RB flask. Close the flask using a cork, by inserting a jet tube and a syringe(containing water)Spray some water inside the flask using syringe.. Shake the flask well and place the apparatus.in a beaker containing water with some phenolphthalein (the jet tube must touch the water in beaker) Observation: colored fountain Inference: ammonia is soluble in water.

4. Reversible and irreversible reactions Reaction which occur in both forward and backward directions simultaneously is called reversible reactions. Reactions taking place in only one direction is called irreversible Reactions. When reactants reacts to form products in a reversible reaction, it is a forward reaction. When products splits to form the reactants in a reversible reaction, It is a backward reaction.

5. Equilibrium state A state in which rate of forward and backward reaction Become same is called equilibrium state. Here the speed of both forward and backward reactions will be same .

6. Le Chatelier’s Principle If a change in concentration, pressure or temperature is brought About in a system at equilibrium, the system will readjust by itself So as to cancel the effect of the change, thus attaining a new Equilibrium state. This is Le Chatelier’s Principle

7. How manufacture of ammonia is related with Le Chatelier’s principle Concentration: concentration of reactant is increased, forward reaction become fast and we will get a satisfactory and good yield of ammonia. Pressure: when pressure increased, the system will try to decrease the pressure to attain equilibrium. To reduce pressure, no: of molecules Must be lowered. Temperature: in the case of ammonia, forward reaction is exothermic and backward reaction is endothermic. Temperature must be lowered to get a good yield. An optimum temperature of 500 degree c. Is used here. Catalyst: catalyst help in attaining equilibrium fast. In the production of ammonia, Sponge Iron is used as the catalyst.

8. Sulphuric acid King of chemicals Used in storage batteries Used in lab as chemical Soap, detergent etc. Steps in preparing H2SO4 Sulphur reacts with oxygen in air to form sulphur dioxide. SO2 gets oxidised to give sulphur dioxide SO3 is dissolved in 98% H2SO4 to form oleum Further dissolved in water to get H2SO4 Process of manufacturing H2SO4 in industrial scale is called Contact process.

9. Physical properties Colourless liquid When diluted it releases heat. Chemical properties when we add H2SO4 to a test tube containing sugar, we will get carbon as the product. Conc. H2SO4 reacts with CuSO4 5H2O to get anhydrous CuSO4 H2SO4 is a good dehydrating agent. H2SO4 is a good drying agent in order to make SO2 and HCL free from moisture When manufactured in lab

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