The incorrect order is : — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Evaluate the orders. (a) 2pπ-2pπ overlap of N-O is stronger than 3pπ-2pπ of P-O (correct). (b) Thermal stability of silicon tetrahalides decreases as the Si-X bond strength decreases down the group (correct). (d) Ionic character and lattice energies of these bromides dictate that melting points decrease from CaBr2 to BeBr2 (correct). Step 2: (c) Arrhenius acid character represents the ease of releasing H+ ions in water, which depends on the M-H bond dissociation energy. Down the oxygen group, the M-H bond weakens, making H2Te a much stronger acid than H2S. Step 3: Therefore, the correct acidic strength order is H2S < H2Se < H2Te. Stating H2S > H2Se > H2Te is incorrect, which corresponds to option (c).