Following compounds A and B have similar structure with delocalization of \pi-electron system.
(A) (PNCl2)x/2 (B) (CH)x
If value of x is 6, then calculate value of "P / Q", where 'P' is total no

Question

Following compounds A and B have similar structure with delocalization of \pi-electron system.
(A) (PNCl2)x/2 (B) (CH)x
If value of x is 6, then calculate value of "P / Q", where 'P' is total no. of \sigma-bonds in compound A and B and 'Q' is total no. of \pi bond in compound A and B.

Prashant Kotian · Accepted Answer

Correct answer: 4

**SOLUTION:**
(A) IS (PNCL2)3. TOTAL \SIGMA-BONDS = 12. TOTAL \PI-BONDS = 3.
(B) IS (CH)6 (BENZENE). TOTAL \SIGMA-BONDS = 12. TOTAL \PI-BONDS = 3.
P = 12 + 12 = 24.
Q = 3 + 3 = 6.
P / Q = 24 / 6 = 4.. Step 1: The melting point of ionic solids is directly proportional to their lattice energy. Step 2: Lattice energy is proportional to the product of ionic charges (q1 * q2) and inversely proportional to the interionic distance (r_c + r_a). MgO and BaO have charges of +2 and -2 (product = 4), whereas NaCl and KCl have charges of +1 and -1 (product = 1). Step 3: Comparing MgO and CaO/SrO/BaO, since Mg^2+ is the smallest cation among the alkaline earth metals, MgO has the shortest interionic distance and therefore the highest lattice energy and melting point. Thus, option (c) is correct.

💡 Solution & Explanation

Practice 22,000+ questions like this