Reactions of Organic Compounds: Quiz

Reactions of Organic Compounds: Quiz

7 questions

1. Question 1EasyCH₂=CH₂ + Br₂ → CH₂BrCH₂Br is an example of:

   AadditionBsubstitutionCeliminationDcondensation
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   Answer: addition

   Two molecules join to form one product and the C=C becomes C–C.

2. Question 2EasyWhich compound decolourises bromine water?

   AhexaneBhex-1-eneCethanolDethanoic acid
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   Answer: hex-1-ene

   Only the alkene has a C=C, which adds bromine.

3. Question 3MediumWhat is formed when propan-2-ol is warmed with acidified potassium dichromate?

   ApropanalBpropanoic acidCpropanoneDpropene
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   Answer: propanone

   Propan-2-ol is a secondary alcohol, so it is oxidized to a ketone: propanone.

4. Question 4MediumWhat reagent and condition convert ethanol into ethene?

   AH₂ with a Ni catalystBconcentrated H₂SO₄, heatCacidified K₂Cr₂O₇DCl₂ in UV light
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   Answer: concentrated H₂SO₄, heat

   This is elimination (dehydration): water is removed and a C=C forms.

5. Question 5MediumWhich alcohol is NOT oxidized by acidified dichromate?

   AethanolBpropan-1-olCpropan-2-olD2-methylpropan-2-ol
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   Answer: 2-methylpropan-2-ol

   It is a tertiary alcohol: the carbon bearing the –OH has no hydrogen, so it cannot be oxidized.

6. Question 6HardWhat is the major product when HBr adds to propene?

   A1-bromopropaneB2-bromopropaneC1,2-dibromopropaneDbromopropene
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   Answer: 2-bromopropane

   Markovnikov's rule: H adds to the end carbon (which has more H), and Br to the middle carbon.

7. Question 7MediumHow many moles of Br₂ react with 0.200 mol of but-1-ene?

   A0.100 molB0.200 molC0.400 molD0.800 mol
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   Answer: 0.200 mol

   One C=C adds one Br₂ (1 : 1), so 0.200 mol C₄H₈ reacts with 0.200 mol Br₂.