Exams › JEE Advanced › Chemistry

Which of the following statements about the halogenation of alkanes are correct?

1. Methane does not react with chlorine in the dark.
2. Photobromination of 2-methylpropane gives a mixture of 1-bromo-2-methylpropane and 2-bromo-2-methylpropane in the ratio 9:1.
3. If methane is taken in large excess relative to chlorine, chlorination can be limited almost entirely to the monochlorinated product.
4. Fluorination of methane requires the use of light or heating to a high temperature.

Correct answer: Methane does not react with chlorine in the dark.

Solution

Statements A and C are correct. B is incorrect because the high selectivity of bromination strongly favors the tertiary product (2-bromo-2-methylpropane), not a 9:1 ratio favoring the primary product. D is incorrect because fluorination proceeds readily even without light due to its high exothermicity.

Related JEE Advanced Chemistry questions

• Even though the chlorination of methane releases energy, why is a high temperature necessary for the reaction to occur?
• Acetylene (HC≡CH) undergoes the following two-step transformation: Step 1: Passed over a red-hot iron tube at 873 K (cyclic trimerisation). Step 2: The product of Step 1 is treated with CO, HCl, and AlCl3 (Gattermann-Koch reaction). How many carbon atoms in the final product are sp2 hybridised?
• Which of the following species is non-aromatic (i.e., neither aromatic nor antiaromatic)?
• Among the following compounds, which one produces ONLY oxalic acid (HOOC-COOH) as the major product when treated with O3 followed by H2O2?
• Which of the following reactions proceeds in the forward direction as written?
• What reagent(s) can convert 1,3-dibromopropane (Br-CH2-CH2-CH2-Br) into acetylene (H-C≡C-H)?

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →