Cracking, alkenes and the bromine water test
10th grade (Year 11 in England) · 16 questions · Common Core: NGSS.HS-PS1-2 · England: GCSE Combined Science: Organic chemistry
Name
Date
Score/ 16
Question 1
Alkenes and cracking: which statement is NOT true?
- A. Alkenes are more reactive than alkanes.
- B. Alkenes contain a carbon–carbon double bond.
- C. Ethene can be used to make the polymer poly(ethene).
- D. Alkanes decolourise bromine water.
Question 2
Bromine water is shaken with a hydrocarbon and turns from orange to colourless. What does this show?
- A. The hydrocarbon is an alkane
- B. The hydrocarbon is an alkene (it has a C=C double bond)
- C. The bromine has evaporated
- D. The hydrocarbon contains oxygen
Question 3
Cracking: C₉H₂₀ → C₇H₁₆ + an alkene. How many hydrogen atoms are in one molecule of the alkene?
Answer
Question 4
Alkenes and cracking: which statement is NOT true?
- A. Alkenes are more reactive than alkanes.
- B. Alkenes contain a carbon–carbon double bond.
- C. Cracking makes longer molecules from shorter ones.
- D. Ethene can be used to make the polymer poly(ethene).
Question 5
Why do refineries crack long-chain hydrocarbons?
- A. To remove all the carbon
- B. To make crude oil
- C. There is more demand for shorter chains such as petrol, and alkenes make polymers
- D. Long chains are too useful
Question 6
Cracking: C₁₅H₃₂ → C₁₂H₂₆ + an alkene. How many hydrogen atoms are in one molecule of the alkene?
Answer
Question 7
Alkenes and cracking: which statement is NOT true?
- A. Cracking is a thermal decomposition reaction.
- B. Alkanes decolourise bromine water.
- C. Alkenes are more reactive than alkanes.
- D. Alkenes contain a carbon–carbon double bond.
Question 8
Bromine water is shaken with a hydrocarbon and turns from orange to colourless. What does this show?
- A. The hydrocarbon contains oxygen
- B. The hydrocarbon is an alkane
- C. The bromine has evaporated
- D. The hydrocarbon is an alkene (it has a C=C double bond)
Question 9
Cracking: C₁₂H₂₆ → C₁₀H₂₂ + an alkene. How many hydrogen atoms are in one molecule of the alkene?
Answer
Question 10
Alkenes and cracking: which statement is NOT true?
- A. Methene is the smallest alkene.
- B. Cracking is a thermal decomposition reaction.
- C. Alkenes contain a carbon–carbon double bond.
- D. Ethene can be used to make the polymer poly(ethene).
Question 11
Bromine water is shaken with a hydrocarbon and turns from orange to colourless. What does this show?
- A. The hydrocarbon is an alkene (it has a C=C double bond)
- B. The hydrocarbon contains oxygen
- C. The bromine has evaporated
- D. The hydrocarbon is an alkane
Question 12
Cracking: C₁₆H₃₄ → C₁₃H₂₈ + an alkene. How many hydrogen atoms are in one molecule of the alkene?
Answer
Question 13
Alkenes and cracking: which statement is NOT true?
- A. Alkenes are more reactive than alkanes.
- B. Ethene can be used to make the polymer poly(ethene).
- C. Cracking makes longer molecules from shorter ones.
- D. Alkenes contain a carbon–carbon double bond.
Question 14
Which conditions are used for catalytic cracking?
- A. dissolving the oil in water
- B. vaporised hydrocarbons passed over a hot catalyst
- C. adding acid at room temperature
- D. freezing the oil
Question 15
Cracking: C₉H₂₀ → C₅H₁₂ + an alkene. How many hydrogen atoms are in one molecule of the alkene?
Answer
Question 16
Alkenes and cracking: which statement is NOT true?
- A. Alkanes decolourise bromine water.
- B. Ethene can be used to make the polymer poly(ethene).
- C. Alkenes contain a carbon–carbon double bond.
- D. Cracking is a thermal decomposition reaction.
Write your answers right on the page. · Free from eurekami.com