NEET Chemistry Question (2026) — Solution

Step-by-step solution

Carbon has a strong tendency to form p -p multiple bonds with itself, such as in alkenes and alkynes. Thus, the first statement is correct. BCl _3 exists as a monomer because boron cannot expand its octet to form a dimer, whereas AlCl _3 exists as a dimer ( Al _2 Cl _6) to complete its octet. Thus, the second statement is correct. The catenation property depends on the element-element bond strength. The bond enthalpy decreases down the group, so the order of catenation is C >> Si > Ge Sn. Thus, the third statement is correct. Oxygen exhibits a -2 oxidation state in most of its compounds, but it also exhibits a -1 oxidation state in peroxides (e.g., H _2 O _2), a -1/2 oxidation state in superoxides (e.g., KO _2), and positive oxidation states when bonded to fluorine (e.g., +2 in OF _2 and +1 in O _2 F _2). Thus, the fourth statement is incorrect. Answer: Oxygen exhibits only -2 oxidation state.