Química - Química Orgânica Practice Questions
ENEM (Brazil) · ENEM Ciências da Natureza · 144 free MCQs with instant results and detailed explanations.
144
Total
43
Easy
72
Medium
29
Hard
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Sample Questions from Química - Química Orgânica
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Q1
Easy
What is the functional group of alcohols?
A.
-OH
B.
-COOH
C.
-NH2
D.
-CHO
Show Answer & Explanation
Correct Answer: A
Alcohols contain a hydroxyl group (-OH) as their functional group, which characterizes them as alcohol compounds. The other options represent different functional groups such as carboxylic acids (-COOH), amines (-NH2), and aldehydes (-CHO).
Q2
Easy
Which of the following is a characteristic of alkanes?
A.
They contain double bonds.
B.
They are saturated hydrocarbons.
C.
They are aromatic compounds.
D.
They contain oxygen atoms.
Show Answer & Explanation
Correct Answer: B
Alkanes are saturated hydrocarbons, meaning they contain only single bonds between carbon atoms. This distinguishes them from alkenes (which have double bonds), aromatic compounds (which have cyclic structures), and compounds with oxygen atoms.
Q3
Easy
Which of the following compounds is an example of a ketone?
A.
Propylene glycol
B.
Acetone
C.
Ethanol
D.
Acetic acid
Show Answer & Explanation
Correct Answer: B
Acetone is a ketone because it has a carbonyl group (C=O) located between two carbon atoms. Propylene glycol is an alcohol, ethanol is also an alcohol, and acetic acid is a carboxylic acid.
Q4
Medium
Which of the following functional groups is characteristic of alcohols?
A.
Aldehyde
B.
Ketone
C.
Hydroxyl
D.
Carboxyl
Show Answer & Explanation
Correct Answer: C
Alcohols are characterized by the presence of a hydroxyl (-OH) functional group, making option C the correct answer.
Q5
Medium
What is the main product of the complete combustion of propane (C3H8)?
A.
Carbon Dioxide and Water
B.
Carbon Monoxide and Water
C.
Ozone and Water
D.
Hydrogen and Carbon Dioxide
Show Answer & Explanation
Correct Answer: A
The complete combustion of propane produces carbon dioxide (CO2) and water (H2O), making option A the correct answer.
Q6
Medium
Which of the following compounds is an example of a saturated hydrocarbon?
A.
C2H4
B.
C3H8
C.
C5H10
D.
C6H12O
Show Answer & Explanation
Correct Answer: B
Saturated hydrocarbons contain only single bonds between carbon atoms, making propane (C3H8) the correct example of a saturated hydrocarbon.
Q7
Medium
Which type of reaction is represented by the equation: R-OH + HCl → R-Cl + H2O?
A.
Hydration
B.
Dehydration
C.
Substitution
D.
Addition
Show Answer & Explanation
Correct Answer: C
This equation shows a substitution reaction where the hydroxyl group of the alcohol is replaced by a chlorine atom, so option C is correct.
Q8
Hard
What is the main functional group present in carboxylic acids?
A.
Aldehyde
B.
Alcohol
C.
Carboxyl
D.
Amine
Show Answer & Explanation
Correct Answer: C
The carboxyl functional group (-COOH) is characteristic of carboxylic acids. Aldehydes contain a carbonyl group, alcohols have hydroxyl groups, and amines contain nitrogen, making option C the correct answer.
Q9
Hard
Which of the following compounds is an example of an alkane?
A.
C3H8
B.
C2H4
C.
C6H10
D.
C4H6O2
Show Answer & Explanation
Correct Answer: A
C3H8, also known as propane, is an alkane, which is a saturated hydrocarbon containing only single bonds between carbon atoms. The other options represent alkenes or compounds with functional groups.
Q10
Hard
What is the major product of the complete combustion of hexane (C6H14)?
A.
C6H12O6
B.
C6H10
C.
CO2 and H2O
D.
C6H6
Show Answer & Explanation
Correct Answer: C
The complete combustion of hexane produces carbon dioxide (CO2) and water (H2O) as major products, indicating that all carbon and hydrogen in hexane are converted into these compounds during the combustion process.
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Química - Química Orgânica — ENEM (Brazil) ENEM Ciências da Natureza Practice Questions Online
This page contains 144 practice MCQs for the chapter Química - Química Orgânica in ENEM (Brazil) ENEM Ciências da Natureza. The questions are organized by difficulty — 43 easy, 72 medium, 29 hard — so you can choose the right level for your preparation.
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