Order of covalent bond: A) KF>KI; LiF>KF B) KF >KI; LiF>KF C) SnCl4>SnCl2; CuCl>NaCl D) KF<KI; CuCl>NaCl Choose the correct answer from the options given below :

To determine the correct answer, we need to compare the strengths of the covalent bonds in the given compounds.

Option A states that KF has a stronger covalent bond than KI, and LiF has a stronger covalent bond than KF. This is incorrect because the covalent bond strength generally increases with increasing electronegativity difference between the bonded atoms. In this case, the electronegativity difference between K and F is smaller than that between K and I, so KI should have a stronger covalent bond than KF. Therefore, option A is incorrect.

Option B states the same incorrect comparison as option A, so it is also incorrect.

Option C compares the covalent bonds in SnCl4 and SnCl2, and CuCl and NaCl. The electronegativity difference between Sn and Cl is the same in both compounds, so the covalent bond strength should be similar. However, Cu has a higher electronegativity than Na, so CuCl should have a stronger covalent bond than NaCl. Therefore, option C is correct.

Option D states that KF has a weaker covalent bond than KI, and CuCl has a stronger covalent bond than NaCl. This is the opposite of what we have established earlier, so option D is incorrect.

Therefore, the correct answer is option C: SnCl4 > SnCl2; CuCl > NaCl.