FYUG EVEN SEMESTER EXAM, 2024 CHEMISTRY (2nd Semester) Course No.: CHMIDC-151T (Indian Chemistry Through the Ages)

Time: 3 Hours | Full Marks: 70 | Pass Marks: 28

SECTION-A

Answer any twenty questions (All solved for full coverage): 1 x 20 = 20

1. Mention two important properties of metals.

Metals are generally malleable (can be beaten into thin sheets).

Metals are excellent conductors of heat and electricity.

2. Define boiling point.

Boiling point is the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid.

3. Define coordinate covalent bonding with example.

A coordinate covalent bond is a type of covalent bond in which both electrons come from the same atom. Example: The formation of the ammonium ion (NH4+) where the lone pair of nitrogen is donated to a proton (H+).

4. What is meant by global warming?

Global warming is the long-term heating of Earth's climate system observed since the pre-industrial period due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere.

5. Write the scientific notations:

(a) 6000 x 10²: 6.0 x 10⁵.

(b) 0.0000423: 4.23 x 10⁻⁵.

6. What do you mean by alchemy?

Alchemy is an ancient branch of natural philosophy that aimed to transform base metals into noble metals (like gold) and sought the "elixir of life" for immortality.

7. Who is considered the father of Rasashastra?

Acharya Nagarjuna is considered the father of Rasashastra (the science of mercury and minerals).

8. What is meant by Iatrochemistry?

Iatrochemistry is a branch of both chemistry and medicine that seeks to provide chemical solutions to diseases and medical ailments.

9. What is the name of the book written by Acharya Nagarjuna on chemistry?

Rasaratnakara.

10. Mention one important contribution of 'Siddha Nityanatha' in ancient chemistry.

Siddha Nityanatha is known for his work Rasaratnakara, which discusses various metallurgical processes and the medicinal use of minerals.

11. Name the primary constituent of glass.

Silica (Silicon dioxide, SiO2).

12. Give examples of coinage metals.

Copper, Silver, and Gold.

13. Mention the uses of ink.

Ink is primarily used for writing, printing, and drawing on surfaces like paper or parchment.

14. What is meant by metallurgy?

Metallurgy is the branch of science and technology concerned with the properties of metals and their production and purification.

15. Mention the characteristic of a good cosmetic.

A good cosmetic should be non-toxic, non-irritating to the skin, and stable over time.

16. Who is considered as the father of Indian chemistry?

Acharya Prafulla Chandra Ray (P. C. Ray).

17. Which pharmaceutical company was founded by Acharya P. C. Ray?

Bengal Chemical & Pharmaceutical Works.

18. Name the book on chemistry written by Acharya P. C. Ray.

A History of Hindu Chemistry.

19. Who was the first Indian to receive Ph.D. degree in chemistry?

Acharya P. C. Ray (from the University of Edinburgh).

20. Name an important discovery made by Acharya Prafulla Chandra Ray.

The discovery of Mercurous Nitrite in 1896.

21. Who is known for interpreting the genetic code and understanding protein synthesis?

Hargobind Khorana.

22. Name the prestigious prize awarded annually to Indian scientists, named after a renowned chemist.

The Shanti Swarup Bhatnagar Prize.

23. What research area earned Venkatraman Ramakrishnan the Nobel Prize in chemistry?

His studies on the structure and function of the ribosome.

24. What significant biochemical compounds did Yellapragada Subbarow discover?

He discovered ATP (Adenosine Triphosphate) and phosphocreatine.

25. Name two medical ailments for which Dr. Asima Chatterjee formulated medications.

Epilepsy (Ayu-S) and Malaria.

SECTION-B

Answer any five questions: 2 x 5 = 10

26. Draw the Lewis dot structure of the following: [2]

(a) CH4: Carbon at center with 4 dots (valency), each paired with one dot from a Hydrogen atom.

(b) SO4²⁻: Sulfur center surrounded by 4 Oxygen atoms, with extra electrons to account for the -2 charge.

27. Differentiate between covalent bonding and ionic bonding. [2]

Ionic Bonding	Covalent Bonding
Involves complete transfer of electrons from one atom to another.	Involves sharing of electron pairs between atoms.
Occurs between metals and non-metals.	Generally occurs between non-metals.

28. What are the different categories of chemical substances in Rasashastra? [2]

Chemical substances in Rasashastra are categorized as Maharasa, Uparasa, Sadharanarasa, Ratna (Gems), Loha (Metals), and Visha (Poisons).

29. What do you mean by Navaratnas? Name them. [2]

Navaratnas refers to the nine sacred gemstones in Indian tradition. They are: Ruby, Pearl, Red Coral, Emerald, Yellow Sapphire, Diamond, Blue Sapphire, Hessonite, and Cat's Eye.

30. What are dyeing agents? Give examples. [2]

Dyeing agents are substances used to impart color to textiles, leather, or food. Examples: Indigo, Turmeric, and Madder.

31. What are perfumes? Mention their uses. [2]

Perfumes are mixtures of fragrant essential oils or aroma compounds. Uses: Used to provide a pleasant scent to the body, clothes, or living spaces and in religious ceremonies.

SECTION-C

Answer any five questions: 8 x 5 = 40

36. What is acid rain? Discuss the causes and impact of acid rain. [2+3+3=8]

Definition: Acid rain is precipitation that has a pH lower than 5.6, making it acidic.

Causes: It is caused by the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere, primarily from burning fossil fuels and industrial processes. These react with water and oxygen to form sulfuric and nitric acids.

Impact:

Environment: Acidifies lakes and streams, harming aquatic life.

Agriculture: Damages forests and leeches nutrients from the soil.

Infrastructure: Corrodes metal structures and damages marble or limestone buildings/statues.

37. Greenhouse Effect: Causes, Impact, and Mitigation. [2+4+2=8]

Definition: The greenhouse effect is a natural process where certain gases in the atmosphere trap heat, keeping the planet warm.

Causes: Increased levels of greenhouse gases like CO2, methane (CH4), and nitrous oxide due to industrialization, deforestation, and fossil fuel combustion.

Impact: Global warming, melting of polar ice caps, rising sea levels, and extreme weather patterns.

Mitigation: Reducing carbon emissions, transitioning to renewable energy (solar/wind), and extensive afforestation.

40. What are soaps? Surfactants and Cleansing Action. [2+2+4=8]

Soaps: Soaps are sodium or potassium salts of long-chain fatty acids.

Surfactants: Types include Anionic, Cationic, Non-ionic, and Amphoteric surfactants.

Cleansing Action: Soap molecules have a hydrophilic head (water-loving) and a hydrophobic tail (oil-loving). In water, they form micelles around oil/grease particles, with the tails attaching to the oil and heads facing the water, allowing the oil to be washed away.

42. Ray's Stages of Chemistry and Honours. [5+3=8]

Acharya P. C. Ray classified the development of Indian chemistry into five stages: 1. The Pre-Vedic/Vedic period, 2. The Ayurvedic period, 3. The Transitional period, 4. The Tantric period, and 5. The Iatrochemical period.

Honours:

CIE (Companion of the Order of the Indian Empire).

Knighthood (Sir P. C. Ray).

Honorary Doctorate from several universities.

44. Research Contributions of Hargobind Khorana. [8]

Prof. Hargobind Khorana made ground-breaking contributions to molecular biology by deciphering the genetic code. He demonstrated how the order of nucleotides in nucleic acids determines the sequence of amino acids in proteins. He was the first to chemically synthesize an artificial gene. His work laid the foundation for modern biotechnology and genetic engineering, earning him the Nobel Prize in Physiology or Medicine in 1968.

Exam Focus Enhancements

Important Scientists & Their Works

P. C. Ray: Mercurous Nitrite; "A History of Hindu Chemistry".
Nagarjuna: "Rasaratnakara"; Father of Rasashastra.
Y. Subbarow: Discovery of ATP.
V. Ramakrishnan: Ribosome structure (Nobel Prize).

Exam Tips

In Section C, use bullet points for "Causes" and "Impacts" to ensure clarity.

Mention specific dates (e.g., discovery of Mercurous Nitrite in 1896) to improve quality.

Clearly distinguish between "Ionic" and "Covalent" bonds using a table.