nitrogen dioxide

Preparation of Oxygen

Preparation of Oxygen Oxygen is prepared in lab generally in two ways either by the application of heat or no application of heat. Using heat: Oxygen in lab is prepared by heating the mixture of powdered potassium chlorate and manganese dioxide in the ratio 4:1 in a hard glass test tube. The oxygen gas is observed in a gas jar through the downward displacement of water. The reaction involved is given below: 2KClO3−→−−−−−MnO2200−300∘C2KCl+3O2↑ Without heat:  The dry sodium peroxide is taken in a conical flask and the apparatus is fitted as shown in figure. The two necks of woulfe’s bottle ... Read more

Preparation of nitrogen

  Preparation of nitrogen Nitrogen is found in both free and combined states. It occupies 78.07% by volume. Nitrogen can be prepared: By heating copper in air: Firstly, air is passed through lime water and then concentrated sulphuric acid to make the air free from carbon dioxide and moistures respectively. The air contains only nitrogen and oxygen which are passed over the heated copper wire as shown in the figure. Here copper combines with oxygen to make copper oxide and nitrogen gas passes over. This nitrogen can be collected by downward displacement of water. By burning phosphorous in air: Nitrogen ... Read more

Types of pollution and their management; air, water, soil, sound/noise, radioactive and e-waste. Industrial waste and its management. Impact of Solid Waste Management, recycling and reuse,

ENVIRONMENT POLLUTION defined as ‘an addition or excessive addition of certain materials to the physical environment (water, air and lands), making it less fit or unfit for life’. Pollutants are the materials or factors, which cause adverse effect on the natural quality of any component of the environment. Classifications 1. According to the form in which they persist after release into the environment. • Primary pollutants: These persist in the form in which they are added to the environment e.g. DDT, plastic. • Secondary Pollutants: These are formed by interaction among the primary pollutants. For example, peroxyacetyl nitrate (PAN) is ... Read more