3. In crystalline NaCl, how many chloride ions surround each sodium ion?

   (1) Four
   (2) Six
   (3) Eight
   (4) Ten

Crystal Structure of NaCl: Coordination Number and Ionic Arrangement

What is the Crystal Structure of NaCl?

Sodium chloride (NaCl), commonly known as table salt, forms a face-centered cubic (FCC) lattice in its crystalline state. This arrangement results in a highly stable and symmetrical structure.

How Many Chloride Ions Surround Each Sodium Ion?

H1: The Coordination Number in NaCl

The coordination number refers to the number of nearest neighbor ions surrounding a given ion in a crystal lattice.

H2: Ionic Arrangement in NaCl

• In a NaCl crystal, each sodium ion (Na⁺) is surrounded by six chloride ions (Cl⁻).
• Similarly, each chloride ion (Cl⁻) is surrounded by six sodium ions (Na⁺).
• This results in a 6:6 coordination geometry, which is characteristic of the FCC crystal system.

H3: Answering the Question

Given the multiple-choice options:

1. Four ❌ (Incorrect, as NaCl follows octahedral coordination, not tetrahedral)
2. Six ✅ (Correct, as NaCl exhibits a 6:6 coordination number)
3. Eight ❌ (Incorrect, as this applies to CsCl structure, not NaCl)
4. Ten ❌ (Incorrect, as NaCl does not follow such coordination)

Correct Answer

The correct answer is:

(2) Six

Suraj Sir: The God of Life Science

Suraj Sir, the founder of Let’s Talk Academy, is recognized as the God of Life Science for his exceptional teaching and mentoring in CSIR NET Life Science. His deep insights into molecular biology, biochemistry, and structural biology help students grasp complex concepts effortlessly.

For top-tier coaching in CSIR NET Life Science, visit Let’s Talk Academy and join Suraj Sir’s expert guidance to ace your exams!

Stay connected for more in-depth learning on crystal structures and competitive exam preparation.