A Level Organic Chemistry

An organic compound contains 38.4 % carbon, 4.80 % hydrogen and 56.8 % chlorine by mass. What is the empirical formula of the compound?

• C₂H₃Cl
• CH₃Cl
• C₂H₅Cl
• C₃H₅Cl₃

The equation for the dehydration of cyclohexanol, C6H11OH, to cyclohexene, C6H10 is: C6H11OH → C6H10 + H2O 50.0 g of cyclohexanol produced 32.8 g of cyclohexene. [Molar masses / g mol–1 : cyclohexanol = 100; cyclohexene = 82] Calculate the percentage yield of cyclohexene.

• 32.8 %
• 40.0 %
• 65.6 %
• 80.0 %

Which of the following substances, obtained from the fractional distillation of crude oil, has the lowest boiling temperature?

• refinery gas
• kerosene
• diesel oil
• lubricating oil

How many isomers are there of C₅H₁₂?

• Two
• Three
• Four
• Five

In a molecule of ethene, C₂H₄, how many π (pi) bonds are present?

• One
• Two
• Three
• Four

The mechanism of the reaction represented by the equation C₂H₄ + Br₂ → CH₂BrCH₂Br

• Free radical substitution
• Free radical addition
• Electrophilic substitution
• Electrophilic addition

Propene reacts with hydrogen chloride gas to give mainly

• 1-chloropropane (CH₃CH₂CH₂Cl)
• 2-chloropropane (CH₃CHClCH₃)
• 3-chloroprop-1-ene (CH₂=CHCH₂Cl)
• 1,2-dichloropropane (CH₃CHClCH₂Cl)

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following alkenes exhibits E-Z isomerism?

• H3CCH=C(CH3)2
• (CH3)2C=CH2
• H2C=CHCH2CH3
• H3CCH=CHCH3

Which of the following mixtures could not form when octane, C₈H₁₈, is cracked?

• propane + pentene
• butane + butene
• pentane + propene
• heptane + ethene

The following liquids all have the same number of electrons in each molecule. Which one is likely to have the lowest boiling point?

• CH₃CH₂CH₂CH₂OH
• CH₃CH₂CH₂CH₂CH₃
• CH₃C(CH₃)₂CH₃
• CH₃CH(CH₃)CH₂CH₃