Chemistry World

 Acid rain, acid deposition or acid precipitation is a broad term which is any form of precipitation with acidic compounds including sulphuric acid and nitric acid that falls down the Earth in dry or wet form.  pH of acid rain Acid rain have pH less than 5.6 (5.5 or less than 5.5)  Slightly acid rain includes carbonic acid which is weak acid that is formed from CO2 in atmosphere without any pollutants Sources of Acid rain  1. Industrial process ( iron & steel production)  2. Natural disasters ( volcanic erruption, sea sprays)  3. Transportation 4. Industrial combustion  5. Electric utilities 6. Industrial boilers  7. By-product of firing process  8. Natural process ( bacterial action, forest fires etc)  How acid rain formed?  S + O2 -----------> SO2  SO2 + ½O2 --------> SO3  SO3 + H2O ----------> H2SO4  NO2 + H2O ----------> HNO3  Acid Deposition  1. Dry Deposition ( refers to acidic gases ...

 Indoor pollution is due to  Radon  Environment tobacco smoke  Biological pollutants Carbon monoxide Nitrogen dioxide Volatile organic compounds  Respiratory particles  Formaldehyde Asbestos Lead  Pesticides  Let's discuss one by one  Radon  Radon is a colorless orderless gas that is produced from decay of radium. It has low density, therefore it's found in basements.  Sources of Radon  Radon is formed from radium, uranium and rocks like phosphate rocks, granite and shales etc. It's also present in soil, building materials, water wells and basements.  Health effects  Radon is a gas when it further decays into daughter polonium and lead which are solid particles. These solid particles are attached to air particles like dust . As a result they enter into lungs where they cause health problems. Besides, lead and polonium decays here and produce alpha and beta particles, these particles damage DNA and adversely affect hum...

Water pollution occur due to presence of waste products in water. As a result, aquatic life is disturbed.  1. Chemical pollution 2. Organic pollution 3. Inorganic pollution 4. Eutrophication 5. Thermal pollution 6. Microbiological pollution  7. Ground water pollution 8. Thermal pollution 9. Surface water pollution 10. Oil spillage 

 Ozone layer  Ozone is an allotropic form of oxygen which forms a layer in stratosphere (about 50km from Earth's surface) that protects us from Ultraviolet radiations coming from sun.  Occurrence  Most of ozone concentration is present in polar region because there is less U.V B (280-320nm) and less air currents are present. Besides, rate of decomposition is equal to rate of formation of ozone. Ozone is present in two forms  Good Ozone  Bad Ozone  Good Ozone  Ozone layer which is present in stratosphere that protects Earth's surface from Ultraviolet radiations. UV radiation are of three types  UV A ..........(320nm to 400nm)   UV B ..........(280nm to 320nm) UV C ...........( 200nm to 280nm)  Bad Ozone  Ozone present in troposphere which act as a pollutant , therefore it's called as bad Ozone.  Formation of ozone  Ozone is formed in equatorial region then moves to polar region and then towards lower altitude. Ozo...

BOD & COD BOD  Biological oxygen demand measures the amount of oxygen required by microorganisms like Bacteria to oxidize biodegradable wastes in waters.  SI unit  It is measured in mg/l as milligram per liter. In other words, mass of oxygen consumed per liter of solution.  Explanation  Small amount of oxygen is present in water is called as dissolved oxygen which is consumed by water bodies. Microorganisms like Bacteria uses this DO (dissolved oxygen) to oxidize the wastes in water. If large amount of wastes present, number of microorganisms will increase. Hence, higher BOD value, higher oxidation takes place and then amount of DO will begin to decline.  Similarly, if there is no waste body present in bacteria, there will be no bacteria existence in water. Hence the value of BOD will be lower and amount of Dissolved oxygen (DO) would be higher.  Diagrammatically,  Waste-bodies ⬆️~Bacteria⬆️~BOD⬆️~DO ⬇️ Method  Take a water sample conta...

 There are 17 sources of water pollution described below. Let's have a look!  Industrial wastes  Sewage and domestic wastes  Animal wastes  Radioactive wastes  Mining Activities  Marine dumping  Accident oil leakage  Leakage from landfills  Leakage from underground storage  Leakage from sewer line  Burning of fossil fuels  Global warming  Urban development  Detergents  Siltation  Agriculture discharge  Chemical fertilizer and Pesticides 

 Lead  Lead is heavy metal water pollution. It may cause many health problem when it is inhaled with water. It enters in our body and cause many health problems to human life. Causes  Major causes are as follows;  1. Lead pipes in sewage system  In our houses, if sewage system uses pipes made up of lead then it would be one cause of lead poisoning in water. When drinking water pass out from these pipes, lead mixed with water and inhaled by us while drinking water. 2. Aerator  In aerator, debris and lead may produce which may effect the human life 3. Industrial activities Lead is found in paints, printing, welding works and auto mechanic industries etc are major source of lead. Besides industries, mining is also source of lead in +2 oxidation state.  4. In atmosphere  Lead exists in form of PbSO⁴ and PbCO³.  5. Galena (PbS)  Galena also adds lead to water.  6. Gasoline  Leaded gasoline is also source of lead that adds into water...