MISCELLANEOUS AND USEFUL CHEMICAL COMPOUNDS (Part-I)

Sulfur dioxide (SO₂) and oxides of nitrogen {NOₓ, where x = 1, 2, 3} are found in the gases produced by fossil fuels used by humans. These gases react with water vapor and oxygen in the atmosphere to produce sulfuric acid and nitric acid. These acidic water vapors can travel miles through the wind to produce acid rain anywhere.

Chromium oxide (Cr₂O₃) is added to the glass to obtain a green color. The naturally occurring chromium oxide is known as Eskolaite. Chromium is used for making alloys and in electroplating. Salts of cobalt are added to impart a red color to the glass.

Barium nitrate is a colorless inorganic compound with the chemical formula Ba(NO₃)₂. It is toxic in nature and soluble in water. It burns with a green flame.

Manganese dioxide (MnO₂) is used to remove the green color from glass. It is a black-colored substance which reacts with glass and converts into sodium permagnet, clearing the green color of the glass.

Barium Peroxide:

• It is a greyish-white granular solid.
• Its chemical formula is BaO₂.
• It is a non-combustible chemical.
• Though it accelerates the rate of combustion of combustible materials.
• It is used as a bleaching agent, in making Hydrogen Peroxide, aluminum welding, and textile dyeing.

Barium chloride, a salt of barium (Ba), is used for the production of green light in fireworks and firecrackers. Apart from this, sodium nitrate is used to produce yellow color and copper chloride is used to produce the blue color.

Barium chloride, a salt of barium (Ba), is used for the production of green light in fireworks and firecrackers. Apart from this, sodium nitrate is used to produce yellow color and copper chloride is used to produce the blue color.

The evaporation method is used to separate the solute from a solution. Evaporation is the process in which an element or compound changes into a gas state. In chemistry, evaporation is defined as the process in which water changes into a gas state by temperature. The process of evaporation takes place at every temperature, space, and time except the dew point state.

Solute + solvent = solution
Sugar + water = Sherbet

Sugar (solute) is obtained by vaporizing water by evaporation. Hence option (b) will be the most appropriate answer. ​

Among the given options of the questions, burning of wood is a chemical change, while the rest of the alternatives include boiling milk, crushing a can, and expansion of a substance by heating are all physical changes. In chemical changes, one or more new substances are formed, whereas in physical changes no new substances are formed.

Winnowing is not suitable for the process of separation of the components of a mixture, whereas filtration, decantation, and sedimentation are all suitable for the process of separation of the components of a mixture. The winnowing method is used to separate the heavy and light components of a mixture by blowing air.