chapter 7.  ELEMENTS OF GROUPS 16, 17 AND 18 class 12 chemistry textbook solution

3. Answer the following.

xv. What happens when a. Cl2 reacts with F2 in equal volume at 437 K.
b. Br2 reacts with excess of F2.


a. Reaction of Cl2 with F2 in Equal Volumes at 437 K:

When equal volumes of chlorine gas (Cl2) and fluorine gas (F2) react at a high temperature of 437 K, a violent and highly exothermic reaction occurs. This reaction is known as a halogen-halogen reaction, and it leads to the formation of a mixture of chlorine pentafluoride (ClF5) and chlorine trifluoride (ClF3):

3Cl2(g) + 2F2(g) → 4ClF3(g) + Cl2(g)

In this reaction, the chlorine gas (Cl2) reacts vigorously with fluorine gas (F2), resulting in the formation of chlorine trifluoride (ClF3) and chlorine pentafluoride (ClF5). The reaction is highly exothermic, releasing a significant amount of energy in the form of heat and light. It’s essential to carry out this reaction with caution, as it can be explosive and should only be conducted by trained professionals in a controlled environment.

b. Reaction of Br2 with Excess F2:

When bromine gas (Br2) reacts with an excess of fluorine gas (F2), a reaction occurs that leads to the formation of various fluorine bromides. The specific products depend on the stoichiometry of the reaction and the conditions. One possible reaction is the formation of bromine trifluoride (BrF3):

Br2(g) + 3F2(g) → 2BrF3(g)

In this reaction, bromine gas reacts with excess fluorine gas to produce bromine trifluoride (BrF3). Bromine trifluoride is a volatile, yellowish liquid at room temperature and is a powerful fluorinating agent. It is used in various chemical applications, including in the production of uranium hexafluoride (UF6) in the nuclear industry.

The reaction between bromine and fluorine can also lead to the formation of other fluorine bromides, depending on the conditions and reactant ratios. These reactions often involve the replacement of bromine atoms with fluorine atoms in the bromine molecule. It’s important to note that the reaction between bromine and fluorine is highly exothermic and should be conducted with care.

chapter 7.  ELEMENTS OF GROUPS 16, 17 AND 18 Textbook Solution page 164