Here are the paraphrased questions in the same language: 1. What is the functional group of aldehydes

Here are the paraphrased questions in the same language:

1. What is the functional group of aldehydes in the class of alcohols?
2. During the oxidation of secondary alcohols, primarily what is formed: 1) ketones; 2) acids; 3) aldehydes?
3. Match the structural formula of a substance to the name of the homologous series it belongs to:
Substance Formula:
A) CH ≡ CH
B) CH3 – CH2 – CH2 — CHO
C) CH3 – CH2 – CH2 – CH2 OH
D) C6H6
Homologous Series:
Aldehydes
Alcohols
Arenes
Alkenes
Alkynes
4. Which of the listed compounds are homologues of ethanol: A) propanol B) ethylene C) acetylene D) methanol
5. Isomers include 1) benzene and cyclohexane 2) ethanol and ethandiol 3) butene-2 and butadiene 4) ethanol and dimethyl ether
6. A qualitative reaction to aldehydes involves interaction with 1. Calcium carbide; 2. Calcium carbonate; 3. Copper(II) oxide; 4. Silver oxide.
7. When propionaldehyde reacts with hydrogen, predominantly what is formed: 1) propanone 2) propanoic acid 3) propanol 4) propane.
8. Hydrogen can be added to both hydrocarbons: 1) methane and acetylene 2) benzene and hexane 3) cyclopropane and propyne 4) butadiene and 2-methylpropane.
9. Which substance can be obtained by the hydration of ethylene? 1) ethane 2) acetylene 3) chloroethane 4) 1,2-dichloroethane.
10. The mass fraction of carbon in acetylene C2H2 is: A) 77.7% B) 83.3% C) 92.3% D) 93.2%
11. Perform transformations, indicate the conditions of reactions:
CH₄ → C₂H₂ → C₂H₄ → C₂H₅Br → C₂H₅OH → CH₃-COOH → CH₃ -COOCH₃
12. Derive the formula of a substance containing 85.7% carbon and 14.3% hydrogen if the relative density with respect to hydrogen is 28.