Total Marks: 65
Time Allowed: 2 Hours 20 Minutes
Section A: MCQs (12 Marks, 20 Minutes)
(Each MCQ carries 1 mark.)
⦁ Which process is used to concentrate sulfur ores?
a) Froth flotation
b) Roasting
c) Electrolysis
d) Hydration
⦁ What is the molecular formula of benzene?
a) C₂H₆
b) C₃H₈
c) C₆H₆
d) C₆H₁₂
⦁ What is the oxidation state of iron in Fe₂O₃?
a) +2
b) +3
c) +4
d) +5
⦁ Which gas is evolved when sodium carbonate reacts with hydrochloric acid?
a) Hydrogen
b) Oxygen
c) Carbon dioxide
d) Nitrogen
⦁ What type of reaction occurs when an alkene reacts with hydrogen?
a) Substitution
b) Addition
c) Elimination
d) Redox
⦁ What is the catalyst used in the Contact Process?
a) Iron
b) Nickel
c) Vanadium pentoxide (V₂O₅)
d) Copper
⦁ Which polymer is used for making plastic bottles?
a) Polyethylene
b) PVC
c) Nylon
d) PET
⦁ What happens when potassium reacts with water?
a) No reaction
b) Slow bubbling
c) Vigorous explosion
d) Forms a black solid
⦁ The monomer of polythene is:
a) Propene
b) Ethene
c) Styrene
d) Vinyl chloride
⦁ Which of the following is a strong acid?
a) HCl
b) CH₃COOH
c) NH₃
d) NaOH
⦁ The main component of biogas is:
a) Propane
b) Methane
c) Butane
d) Ethanol
⦁ Which compound is used as an antacid?
a) NaCl
b) NaHCO₃
c) KOH
d) H₂SO₄
Section B: Short Questions (33 Marks)
(Attempt any 11 questions, each question carries 3 marks.)
⦁ Define oxidation and reduction with examples. OR Write the oxidation and reduction half-reactions for Zn + CuSO₄ → ZnSO₄ + Cu.
⦁ Write a balanced chemical equation for the reaction between ethene and bromine water. OR Explain the combustion of propane with a balanced equation.
⦁ What is a neutralization reaction? Give an example. OR Write the balanced equation for the reaction of sulfuric acid with sodium hydroxide.
⦁ Describe the process of electrolysis. OR Write the reaction occurring at the cathode during the electrolysis of molten NaCl.
⦁ Explain the preparation of ammonia by the Haber process. OR Write the balanced chemical reactions involved in the Contact Process for sulfuric acid.
⦁ What are polymers? Give two examples. OR Write the reaction equation for the polymerization of ethene.
⦁ Define isomers and give an example. OR What are aromatic hydrocarbons? Give an example.
⦁ Explain the process of cracking in petroleum refining. OR Write the reaction for the hydrogenation of ethene.
⦁ What happens when calcium carbonate is heated? Write the reaction. OR Explain the reaction between quicklime and water with an equation.
⦁ What is saponification? Write the chemical reaction involved. OR Give the reaction of an ester with sodium hydroxide.
⦁ Explain the role of a catalyst in a chemical reaction. OR Why is cryolite used in the extraction of aluminum?
Section C: Long Questions (20 Marks, Each Question = 5 Marks)
(Attempt any 4 questions, each question carries 5 marks and is divided into three parts (a, b, c)
Q1.
a)Write the equation for the oxidation of ethanol to ethanoic acid. (2 marks)
b) How does ethanol react with sodium? Write the reaction. (2 marks)
c) Define esterification and give a reaction example. (1 mark)
OR
a) Write the polymerization reaction of ethene. (2 marks)
b) Differentiate between addition and condensation polymers. (2 marks)
c) Write the reaction of glucose fermentation. (1 mark)
Q2.
a)Write the equation for the electrolysis of molten NaCl. (2 marks)
b) Explain the role of cryolite in aluminum extraction. (2 marks)
c) Describe the rusting of iron with a chemical equation. (1 mark)
OR
a) Write the reaction occurring at the anode during CuSO₄ electrolysis. (2 marks)
b) Why does copper not react with dilute HCl? (2 marks)
c) How is zinc extracted from zinc oxide? Write the reaction. (1 mark)
Q3.
a)Write the reaction for the formation of ozone from oxygen. (2 marks)
b) Explain the role of greenhouse gases in global warming. (2 marks)
c) Describe the harmful effects of acid rain. (1 mark)
OR
a) Write the decomposition reaction of limestone in cement production. (2 marks)
b) Explain how catalytic converters reduce air pollution. (2 marks)
c) Describe how CFCs damage the ozone layer. (1 mark)
Q4.
a) Write the balanced equation for the production of ammonia by the Haber process. (2 marks)
b) Explain how pressure affects ammonia yield. (2 marks)
c) What happens when ammonia dissolves in water? (1 mark)
OR
a) Write the balanced equation for sulfuric acid formation in the Contact Process. (2 marks)
b) Explain the importance of vanadium pentoxide in this process. (2 marks)
c) What happens when sulfuric acid reacts with zinc? (1 mark)