Even though the crystal radii of both K+ and Ag+ are almost same, the melting point of AgCl is only 455°C, while that of KCl is 776°C. The best explanation is:
A. AgCl has more ionic character than KCl due to greater polarizing power of potassium ion.
B. KCl has more ionic character than AgCl due to greater polarizing power of potassium ion.
C. AgCl has more covalent character than KCl due to greater polarizing power of silver ion.
D. KCl has more covalent character than AgCl due to greater polarizing power of silver ion.
Answer:C
Even though the crystal radii of both K+ and Ag+ are almost same, the melting point of AgCl is only 455°C, while that of KCl is 776°C. The best explanation is:
A. AgCl has more ionic character than KCl due to greater polarizing power of potassium ion. B. KCl has more ionic character than AgCl due to greater polarizing power of potassium ion. C. AgCl has more covalent character than KCl due to greater polarizing power of silver ion. D. KCl has more covalent character than AgCl due to greater polarizing power of silver ion.
Explanation: The K+ ion has octet configuration in the outer shell (3s23p6). Therefore it has less polarizing power and hence KCl is more ionic. Whereas, in Ag+ ion, there is pseudo octet configuration (4s24p64d10) in its outer shell. Therefore it has greater polarizing power due to ineffective shielding of nuclear charge by d-electrons.