To determine which statement is incorrect, let's analyze each option one by one, focusing on the chemical reactions involved.
Examining Each Statement
Statement (a): Br2 reacts with hot and strong NaOH solution to give NaBr and H2O.
This statement is accurate. When bromine (Br2) reacts with a hot, concentrated sodium hydroxide (NaOH) solution, it undergoes a reaction known as the bromine-sodium hydroxide reaction. The products of this reaction include sodium bromide (NaBr) and water (H2O), along with sodium bromate (NaBrO3) as a minor product. Thus, this statement is correct.
Statement (b): Ozone reacts with SO2 to give SO3.
This statement is also true. Ozone (O3) can oxidize sulfur dioxide (SO2) to sulfur trioxide (SO3). This reaction is significant in atmospheric chemistry, particularly in the formation of acid rain. Therefore, this statement holds up under scrutiny.
Statement (c): Silicon reacts with NaOH(aq) in the presence of air to give Na2SiO3 and H2O.
This statement is correct as well. Silicon (Si) can react with sodium hydroxide (NaOH) in an aqueous solution, especially when oxygen is present (from air). The reaction produces sodium metasilicate (Na2SiO3) and water (H2O). This is a well-documented reaction in inorganic chemistry.
Statement (d): Cl2 reacts with excess of NH3 to give N2 and HCl.
This statement is where the inaccuracy lies. Chlorine gas (Cl2) does react with ammonia (NH3), but the primary products of this reaction are nitrogen trichloride (NCl3) and hydrochloric acid (HCl), not nitrogen gas (N2). While under certain conditions, nitrogen gas can be produced, it is not a typical product of the reaction with excess ammonia. Therefore, this statement is incorrect.
Conclusion
Based on the analysis, the incorrect statement is (d): Cl2 reacts with excess of NH3 to give N2 and HCl. The expected products are primarily NCl3 and HCl, making this statement inaccurate in the context of typical chemical behavior.
