This is Day 57 | 90 Days RAS Mains 2025 Answer Writing, We will cover the whole RAS Mains 2025 with this 90-day answer writing program
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GS Answer Writing – Metal, Non-metal, and Metalloids | Metallurgical Principles and methods, Important ores and alloys | Acid, Base, and Salts, concept of pH and Buffers । Paragraph
Metalloids (Semimetals) are elements that exhibit intermediate properties between metals and nonmetals.
They are located along the zig-zag line in the periodic table, separating metals from non-metals.
- Boron: Used in fireworks for green flames; cleaning agents and pest control.
- Silicon: computer chips; waterproof sealants (silicones).
- Germanium: production of semiconductors
- Arsenic: historically as a pesticide , production of semiconductors
- Antimony: Used in paints and ceramic enamels; as a cosmetic.
- Tellurium: manufacturing of thermoelectric devices for power generation and cooling applications.
- Polonium: Rare and highly radioactive; Limited use due to extreme toxicity
Buffer solutions are aqueous solutions that resist changes in pH when small amounts of acid or base are added to them.
- They prevent changes in pH by utilizing the equilibrium between a weak acid and its conjugate base (or a weak base and its conjugate acid) to neutralize added acid or base, maintaining the pH of the solution within a relatively narrow range.
Eg Blood maintain pH of 7.4 → contain carbonate/bicarbonate buffer

The entire scientific and technological process used for isolation of the metal from its ores is known as metallurgy. Ores are usually contaminated with earthly or undesired materials known as gangue.
The extraction and isolation of metals from ores involve the following major steps:
- Crushing and Grinding : Pulverization ⇒ Find powder is prepared to increase the surface area for chemical reactions.
- Concentration of Ores → Removal of Gauge
- Physical Methods
- Hydraulic washing: based on the differences in gravities of the ore and the gangue particles ⇒ gravity separation. Eg for Gold, Chromium and Iron
- Magnetic Separation : when either the ore or the gangue (one of these two) is capable of being attracted by a magnetic field . Ex Pyrolusite (MnO2) & Chromite (FeO.Cr2O3)
- Froth Floatation : for removing gangue from sulphide ores .{ a suspension of powdered ore is made with water, to which collectors (e.g., pine oils, fatty acids, xanthates) and froth stabilizers (e.g., cresols, aniline) are added.
- Chemical methods
- Leaching: commonly employed when the ore is soluble in suitable solvent.
- Leaching of Alumina from Bauxite: Bauxite is digested with a concentrated solution of NaOH at elevated temperatures and pressures. This leaches out Al2O3 as sodium aluminate, leaving impurities behind.
- Other Examples: silver and gold ⇒ the respective metal is leached with a dilute solution of NaCN or KCN in the presence of air.
- Leaching: commonly employed when the ore is soluble in suitable solvent.
- Conversion of ore into metal oxide:
Heating in the presence of air (roasting) or without air (calcination) to remove volatile impurities, moisture, and sulphur. → Leaving behind metal oxide
Roasting : Primarily for sulphide ores | Calcination → for carbonate ores |
- Reduction of Metal Oxide/smelting (koi si bhi ek reaction sufficient hai )
- Smelting is the process of extracting a metal from its oxide ore by heating it with a reducing agent such as coke (carbon) in a furnace.
- Extraction of copper from cuprous oxide [copper(I) oxide]: Coke as reducing agent
- Cu2O(s)+C(s)→2Cu(s)+CO(g)
- Extraction of zinc from zinc oxide
- ZnO + C → Zn + CO (coke,1673K)
Refining/Purification : Refining methods include distillation, fractional crystallization, liquation, electrolytic refining, zone refining, vapour phase refining, and chromatographic methods.
Paper 4 (Comprehension part) – paragraph
Freedom of Speech and Democracy
Freedom of speech is the fourth pillar of democracy. Democracy is the government for the people, of the people and by the people. This right to express gives us a right to criticise and ask the state to function properly and work as it is obliged to. Freedom of expressions gives us something more than just existence, it gives us a reason to live with dignity. It makes us a social being.
Article 19 of Universal Declaration of Human Rights states: “Everyone has the right to freedom of opinion and expression, this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.”
The right to expression is essential for our autonomy and free will, to an individual’s right to self-development, and to truth seeking.
If citizens are to be able to rule as democracy requires, it’s after all the rule of the people, by the people. If citizens are to be able to rule, they must be able to communicate freely, including with those that they elect and who govern them. They must be free to criticise, question, challenge, all of which requires full access to information and ideas. Freedom of expression teaches tolerance and builds tolerant societies.
In recent years it has been seen that political parties have become so intolerable to matters against them that they choose violence over citizens and it has been found that most of the aggrieved parties had just expressed their general views on social media. Sometimes it is seen that illiterate political supporters who lack the basic knowledge of the English language infer some different meanings of tweets, statements posted by people online.As George Washington said “If freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter.”
Day 57 | 90 Days RAS Mains 2025 Answer Writing
Day 57 | 90 Days RAS Mains 2025 Answer Writing