Q.1: What is the simplest alkyne?
A) Propylene
B) Acetylene
C) Butyne
D) Ethylene
Q.2: What is the molecular formula of acetylene?
A) C2H4
B) C2H2
C) C3H6
D) C4H8
Q.3: Alkynes are also called what?
A) Alkenes
B) Acetylenes
C) Alkanes
D) Aromatics
Q.4: Acetylene does not occur free in which of the following?
A) Water
B) Coal gas
C) Air
D) Organic solvents
Q.5: What is the approximate percentage of acetylene in coal gas?
A) 0.1%
B) 0.06%
C) 0.2%
D) 0.5%
Q.6: How are alkynes prepared from vicinal dihalides?
A) By oxidation
B) By dehydration
C) By dehydrohalogenation
D) By hydrolysis
Q.7: What happens when a vicinal dihalide is heated with alcoholic KOH?
A) A double bond is formed
B) A triple bond is formed
C) A single bond is formed
D) No reaction occurs
Q.8: What is the first member of the alkyne series?
A) Butyne
B) Ethylene
C) Acetylene
D) Propylene
Q.9: What is the physical state of acetylene at room temperature?
A) Solid
B) Liquid
C) Colourless gas
D) Coloured gas
Q.10: How does acetylene smell?
A) Sweet
B) Faint garlic odour
C) Fruity
D) Odourless
Q.11: In which of the following is acetylene slightly soluble?
A) Water
B) Organic solvents
C) Alcohol only
D) Air
Q.12: How does the flammability of alkynes compare to alkanes?
A) Less flammable
B) More flammable
C) Not flammable
D) Same flammability
Q.13: Alkynes contain what type of bond?
A) Single bond
B) Double bond
C) Triple bond
D) Quadruple bond
Q.14: What type of reaction occurs when alkynes react with halogens?
A) Elimination
B) Addition
C) Substitution
D) Hydrolysis
Q.15: What happens to bromine water when added to acetylene?
A) Turns red
B) Discharges red-brown colour
C) No colour change
D) Turns blue
Q.16: What is produced when ethyne is oxidized with alkaline KMnO4?
A) Acetic acid
B) Glyoxal
C) Oxalic acid
D) Ethanol
Q.17: Which reaction is used to identify the unsaturation of alkynes?
A) Oxidation
B) Dehalogenation
C) Hydrolysis
D) Dehydrogenation
Q.18: What is a common use of acetylene in welding?
A) It produces a cold flame
B) It produces an oxy-acetylene flame
C) It does not burn
D) It is used for cooling
Q.19: Acetylene is used to prepare which of the following?
A) Water
B) Alcohols
C) Salts
D) Bases
Q.20: Acetylene is used for which of the following processes?
A) Ripening of fruits
B) Preservation of fruits
C) Fermentation
D) Freezing
Q.21: What is the difference between glycol and glyoxal?
A) Glycol is a gas, glyoxal is a liquid
B) Glycol is a single compound, glyoxal is a mixture
C) Glycol has two hydroxyl groups, glyoxal has two carbonyl groups
D) There is no difference
Q.22: What is the chemical formula of oxalic acid?
A) C2H2O4
B) C2H4O4
C) C2H6O2
D) C2H4O2
Q.23: Which of the following statements is true about acetylene?
A) It is heavier than air
B) It is soluble in water
C) It has a faint garlic odour
D) It is a solid
Q.24: What is the reaction called when two hydrogen atoms are removed from adjacent carbon atoms in alkynes?
A) Hydration
B) Hydrohalogenation
C) Dehydrohalogenation
D) Hydrolysis
Q.25: Which reaction is used to form tetrabromoethane from acetylene?
A) Addition of hydrogen
B) Addition of bromine
C) Dehydrohalogenation
D) Oxidation
Q.26: What type of flame is produced when acetylene is burned in oxygen?
A) Cold flame
B) Smoky flame
C) Oxy-acetylene flame
D) Clear flame
Q.27: What happens during the addition reactions of alkynes?
A) New triple bonds are formed
B) Double bonds are broken and single bonds are formed
C) No bonds are broken
D) All bonds are broken
Q.28: What is the key characteristic of alkynes due to their triple bond?
A) They are inert
B) They are highly reactive
C) They have a pleasant smell
D) They are solids
Q.29: Which solvent is acetylene NOT soluble in?
A) Water
B) Benzene
C) Alcohol
D) Ether
Q.30: Alkynes produce what type of flame compared to alkenes?
A) Cooler flame
B) Brighter flame
C) Smokier flame
D) No flame