General awareness: Science Notes # 2
- Hydrogen is the most abundant element in the universe.
- Hydrogen is the 3rd most abundant on the surface of the earth.
- Hydrogen contains one proton and one electron and it is the first element in the periodic table.
- Harold C.Urey got nobel prize for separating hydrogen isotope of mass number 2.
- The mixture of carbon monoxide and hydrogen is called Water gas or synthetic gas.It is called synthetic gas as it is used for the synthesis of methanol and number of hydrocarbons.
- Hydrogen is lighter than air.
- Largest single use of hydrogen is in the synthesis of ammonia which is used in the manufacture of nitric acid and nitrogenous fertilisers.
- Hydrogen is used in the preparation of vanaspathi, as a rocket fuel in the space research and also in fuel cells for generating electrical energy.
- Water that includes calcium and magnesium salts in the form of hydrogencarbonate, chloride and sulphate in water makes water hard.
- Hardness of water is of two types
- a. permanent hardness
- b. Temporary hardness
- Temporary hardness is due to the presence of magnesium and calcium hydrogen carbonates. It can be removed by boiling and clarks method.
- In Clarks method calculated amount of lime is added to hard water. It precipitates out calcium carbonate and magnesium hydroxide.
- Permanent hardness is due to the presence of soluble salts of magnesium and calciun in the form of chlorides and sulphates in water.
- Permanent hardness is removed by
- a. treatment with washing soda(sodium carbonate)
- b.calgon's method (sodium hexameta phosphate is called calgon).
- c. Zeolite/Permutit process : (hydrated sodium aluminium silicate is Zeolite/Permutit)
- Hydrogen peroxide acts a both acidic and alkaline media.
- Hydrogen peroxide uses: as a hair bleach, as a mild disinfectant, synthesis of hydroquinone, tartaric acid and others
- Heavy water is used as moderator in nuclear reactors.
- Hydrogen on the industrial scale is prepared by water gas shift reaction from petrochemicals.