Selected MCQ

Current Question
Which gas is essential for combustion?
  • A. CO₂
  • B. O₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
Oxygen supports burning.
Related Question 1
Which gas is essential for photosynthesis?
  • A. O₂
  • B. CO₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
CO₂ is carbon source.
Related Question 2
Which gas is needed for combustion?
  • A. CO₂
  • B. O₂
  • C. N₂
  • D. H₂
Correct Answer: B
Explanation:
Oxygen supports burning.
Related Question 3
The major product of complete combustion of an alcohol in excess oxygen is:
  • A. Alkene and water
  • B. Carbon monoxide only
  • C. Carbon dioxide and water
  • D. Aldehyde and hydrogen
Correct Answer: C
Explanation:
Complete oxidation of carbon and hydrogen yields (CO_2) and (H_2O).