Previous Year Question Paper

BT-101 (GS) – Engineering Chemistry

December 2025COMMONSEMESTER-2
December 2025
Max Marks: 70
Duration: 3 Hours
Instructions:

Attempt any five questions.

All questions carry equal marks.

Q.1
a)Unit 1

Define Hardness of water. Explain the various units of hardness and their inter-relationship. Why is EDTA method preferred over other methods for hardness determination?

b)Unit 1

Explain the principle of EDTA titration. Calculate the total hardness (in ppm) of a water sample containing: Ca(HCO3)2 = 16.2 mg/L, Mg(HCO3)2 = 7.3 mg/L, MgCl2 = 9.5 mg/L and CaSO4 = 13.6 mg/L.

Q.2
a)Unit 2

Compare Zeolite and Ion-Exchange processes for water softening. Discuss why Ion-Exchange is superior for high-pressure boilers.

b)Unit 1

What is Desalination? Describe the Reverse Osmosis (RO) process with a neat labeled diagram. State its industrial applications.

Q.3
a)Unit 7

What is periodic table? Write trends of following in a group and in a period giving suitable reasons: (i) electronegativity (ii) electron affinity (iii) atomic size

b)Unit 7

Write brief note on (any two) : (i) Effective nuclear charge (ii) Polarizability (iii) Oxidation states

Q.4
a)Unit 4

Discuss the mechanism of Addition and Condensation polymerization with one example each. Define Functionality of a monomer.

b)Unit 4

Write the synthesis, properties and engineering uses of: (i) Bakelite (ii) PMMA (iii) Neoprene

Q.5
a)Unit 3

Define Lubrication. Explain the mechanism of Extreme Pressure Lubrication. Which type of lubricants are used for heavy-duty machinery?

b)Unit 3

Discuss the importance of Viscosity Index. How does it affect the performance of an engine oil in varying temperatures?

Q.6
a)Unit 6

State the selection rules for IR Spectroscopy. Explain why some molecules are IR Active and some are not. Describe the various types of molecular vibrations.

b)Unit 6

Explain the principle of Thin Layer Chromatography (TLC). How is the Rf value calculated and what does it indicate?

Q.7
a)Unit 5

Explain the Differential Aeration Theory of corrosion with the help of Pitting Corrosion example. Why do iron nails rust faster in saline water?

b)Unit 5

What is Sacrificial Anodic Protection? How is it used to protect underground pipelines? Compare it with Impressed Current Cathodic Protection.

Q.8
a)Unit 2

Explain the chemical reactions involved in the Lime-Soda process. Why is a small amount of coagulant (like Alum) often added during this process?

b)Unit 2

What is lime-soda process? Calculate the requirement of Lime (80% pure) and Soda (90% pure) for treatment of 1,00,000 liters of water containing: Ca(HCO3)2 = 40.5 ppm, Mg(HCO3)2 = 36.5 ppm, MgSO4 = 30 ppm and CaCl2 = 22.2 ppm.