Free account: track your progress — Sign up free

JAMB Chemistry 2018 Objective — Question 11

Question 11 of 36 from the Joint Admissions and Matriculation Board (JAMB) Chemistry 2018 Objective paper, with the correct answer and a full explanation.

Advertisement

20cm³ of a gaseous hydrocarbon was mixed with 150cm³ of oxygen and exploded in a closed vessel at room temperature. After cooling, 110cm³ of gases remained. After absorption by concentrated sodium hydroxide solution, the volume left was 50cm³. The molecular formula of the hydrocarbon is

  • A. C₃H₆Correct
  • B. C₃H₈
  • C. C₄H₁₀
  • D. C₄H₈

Explanation

Volume of CO₂ = 110−50 = 60cm³. Total volume of oxygen used = 150−50 = 100cm³. Using ratios derived from the combustion equation and Avogadro's law: the formula works out to C₃H₆ (propene).

Advertisement

Sign up free to unlock

  • Score tracking
  • Practice history
  • Saved questions
  • Progress dashboard
  • Personalized sessions
  • Weak-topic breakdown

…and/or go further with premium services and No Ads.