p-block Oxoacids of N P S Cl
p-block Elements
52
JEE Qs
8%
Hard
100
min
Focus on understanding the structure and oxidation state of each oxoacid, as these fundamentally determine its acidity, basicity, and redox properties.
🧮 Key Formulas
✅ Key Points for JEE
- 1Mastering the drawing of correct Lewis structures for all oxoacids, including determining central atom, bonds (single/double), and lone pairs, is crucial for understanding their properties.
- 2The oxidation state of the central atom (N, P, S, Cl) dictates the acid's oxidizing/reducing nature and is key to predicting its reactions.
- 3For phosphorus oxoacids, H atoms attached directly to P (P-H bonds) are not acidic, while H atoms attached to oxygen (O-H bonds) are acidic. This determines basicity.
- 4Acidity of oxoacids generally increases with increasing oxidation state of the central atom (e.g., HClO < HClO2 < HClO3 < HClO4) and with increasing electronegativity of the central atom in the same period (e.g., H2SO4 > H3PO4).
- 5Be familiar with the specific properties and reactions (e.g., disproportionation, thermal decomposition) of key oxoacids, especially those with intermediate oxidation states.
⚠️ Common Mistakes
- ✕Incorrectly identifying the basicity (number of acidic protons) of phosphorus oxoacids by counting all H atoms instead of only O-H bonds.
- ✕Confusing the structural differences and resulting properties of various oxoacids, especially isomers or polymers (e.g., ortho, pyro, meta forms of phosphoric acid, or different peroxoacids of sulfur).
- ✕Miscalculating oxidation states or incorrectly assigning oxidizing/reducing properties based on an incomplete understanding of stability and available oxidation states.
📝 Practice Questions
See allQ60.Given below are the atomic numbers of some group 14 elements. The atomic number of the element with lowest melting point is : (1) 6 (2) 82 (3) 14 (4) 50
Q72.A group 15 element forms dπ −dπ bond with transition metals. It also forms hydride, which is a strongest base among the hydrides of other group members that form dπ −dπ bond. The atomic number of the element is ____.
Q70.The maximum covalency of a non-metallic group 15 element ' E ' with weakest E −E bond is : (1) 4 (2) 6 (3) 3 (4) 5
Q65.The incorrect statement among the following is options 1 . (1) PH3 shows lower proton affinity than NH3 . (2) SO2 can act as an oxidizing agent, but not as a reducing agent. (3) PF3 exists but NF5 does not. (4) NO2 can dimerise easily. Q66. 2.8 × 10−3 mol of CO2 is left after removing 1021 molecules from its ' x ' mg sample. The mass of CO2 taken initially is Given: NA = 6.02 × 1023 mol−1 (1) 98 .3 mg (2) 48.2 mg (3) 196 .2 mg (4) 150 .4 mg
Q68.The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of (1) Atomicity (2) Electron gain enthalpy (3) Electronegativity (4) Atomic size
Q44.When MnO2 and H2SO4 is added to a salt (A), the greenish yellow gas liberated as salt (A) is : (1) CaI2 (2) NaBr (3) KNO3 (4) NH4Cl
NCERT Chapters
- Class 12 Chemistry Part 1 Ch 7: The p-Block Elements