Chemistry · PYQ NEET UG 2021

Which of the following reactions is the metal displacement reaction? Choose the right option. Which of the above statements is/are correct?

1. \( \mathrm{Cr}_{2}\mathrm{O}_{3} + 2Al \xrightarrow{\Delta} \mathrm{Al}_{2}\mathrm{O}_{3} + 2Cr \)
2. \( \mathrm{Fe} + 2HCl \rightarrow \mathrm{FeCl}_{2} + \mathrm{H}_{2}\uparrow \)
3. \( 2\mathrm{Pb}(\mathrm{NO}_{3})_{2} \rightarrow 2\mathrm{PbO} + 4\mathrm{NO}_{2} + \mathrm{O}_{2}\uparrow \)
4. \( 2\mathrm{KClO}_{3} \xrightarrow{\Delta} 2\mathrm{KCl} + 3\mathrm{O}_{2} \)