In a NaCl crystal lattice, each Na+ ion is surrounded by six Cl- ions, and each Cl- ion is surrounded by six Na+ ions. The arrangement forms a face-centered cubic (FCC) structure.
This configuration ensures maximum stability through electrostatic attractions between oppositely charged ions, with each ion having a coordination number of 6. Therefore, the coordination number of Na+ in a NaCl crystal is 6.
Explanation:
Correct Answer: 6
If the molar conductivity ($\Lambda_m$) of a 0.050 mol $L^{–1}$ solution of a monobasic weak acid is 90 S $cm^{2} mol^{–1}$, its extent (degree) of dissociation will be:
[Assume: $\Lambda^0$ = 349.6 S $cm^{2} mol^{–1}$ and $\Lambda^0_{\text{acid}}$ = 50.4 S$ cm^{2} mol^{–1}$]