Question

Hydrogen reacts with the following in the dark

(a) Cl₂

(b) F₂

(c) Br₂

(d) 1₂ 

Answer 1

Correct option is: (b) F₂ 

To solve the question "Hydrogen can react with the following even in dark," we need to analyze the options provided and understand the reactivity of hydrogen with different halogens.

1. Understanding the Reactivity of Hydrogen with Halogens:
- Hydrogen can react with halogens to form hydrogen halides (HX), where X represents a halogen (F, Cl, Br, I).
- The general reaction can be represented as:
H₂ + X₂ → 2HX

2. Analyzing Each Option:
- Option A: Iodine (I₂):
- Iodine typically requires heat and a catalyst to react with hydrogen. Therefore, it does not react in the dark.
- Option B: Chlorine (Cl₂):
- Chlorine reacts with hydrogen, but this reaction usually requires sunlight or UV light to initiate. Hence, it does not react in the dark.
- Option C: Fluorine (F₂):
- Fluorine is highly reactive and can react with hydrogen even in the dark. The reaction is:
H₂ + F₂ → 2HF
- This makes fluorine the correct answer.
- Option D: Bromine (Br₂):
- Bromine requires heating and a catalyst to react with hydrogen, so it does not react in the dark.