Chemistry (Part-IX) (Railway)

• For example, Iron which is more reactive than copper displaces copper from copper sulphate solution to form iron sulphate solution.

• Such a process is called dilution.

• Dilution is the process of addition of solvent, which decreases the concentration of the solute in the solution.

• There are four major types of non-renewable resources: oil, natural gas, coal, and nuclear energy.

• Oil, natural gas, and coal are collectively called fossil fuels because they were formed within the Earth from dead plants and animals over millions of years.

• Both the nitrogen atoms share three electrons each and thus, form three covalent bonds and make a nitrogen molecule.

• Each covalent bond is associated with one pair of electrons.

• Acid rain water, if mixed with river water, lowers its pH below 5.6.

• Thus, it makes river water acidic.

• It is often absorbed onto filter paper to produce one of the oldest forms of pH indicator, used to test materials for acidity.

• Acids turn blue litmus red, and bases turn red litmus to blue.

• According to his periodic law, if the elements are arranged in order of increasing atomic masses, then those with similar properties are repeated at regular intervals.

• Moseley perodic table based on atomic mass. moseley is known as father of modern periodic table.

• The atomic mass of Bromine is 81.2; while that of Chlorine and lodine are 35.5 and 126.9 respectively.

• So, Chlorine, Bromine, lodine form a triad.

• Thereby, a molecule of pentane, C₅H₁₂ is heavier than a molecule of propane C₃H₈ by about 28 g/mol.

• It is primarily used in cooking (baking), as a leavening agent.

• It reacts with acidic components in batters, releasing carbon dioxide, which forms. the characteristic texture and grain in pancakes, cakes, quick breads, etc.