In basic inorganic chemistry, what is the correct chemical formula for common salt, also known as sodium chloride?

Introduction / Context:
This question tests simple formula writing skills in inorganic chemistry. Common salt used in food and many industrial processes is sodium chloride. Remembering and recognising the correct formula for sodium chloride is a fundamental skill because it is a classic example of an ionic compound formed from a metal and a non metal.

Given Data / Assumptions:

• The substance in question is sodium chloride, also referred to as common salt.
• We are given several possible formulas containing sodium and chlorine or other elements.
• We assume standard valencies of sodium and chloride ions.

Concept / Approach:
Sodium is a group 1 metal and commonly forms a cation with a single positive charge, written as Na plus. Chlorine is a halogen and forms an anion with a single negative charge, written as Cl minus. To form a neutral ionic compound, one Na plus ion combines with one Cl minus ion. The overall formula is therefore NaCl, indicating a one to one ratio of sodium and chloride ions in the crystal lattice of sodium chloride.

Step-by-Step Solution:

Verification / Alternative check:
Textbooks and packaging labels for table salt consistently use the formula NaCl for sodium chloride. Structural diagrams of the sodium chloride crystal show a lattice with equal numbers of sodium and chloride ions. Chemical equations for reactions involving salt, such as NaOH plus HCl giving NaCl plus water, also confirm the ratio one to one. All of these sources agree that the correct formula for common salt is NaCl and not any of the other formulas listed.

Why Other Options Are Wrong:

• NaCl2: This would imply one sodium ion and two chloride ions, giving a net negative charge and not representing neutral sodium chloride.
• Na2Cl: This would imply two sodium ions and one chloride ion, resulting in a net positive charge and not a neutral compound.
• Na2C: This contains carbon instead of chlorine and does not refer to common salt.
• NaCl3: This again suggests a charge imbalance and is not the formula for common sodium chloride.

Common Pitfalls:
Students sometimes try to match subscripts with group numbers or attempt to create formulas by guesswork without checking charge balance. It is always safer to use ionic charges and cross multiply them to get the simplest neutral ratio. In this simple case, because both sodium and chloride carry charges of magnitude one, the formula reduces to NaCl with no subscripts other than one, which are not written explicitly.

Final Answer:
The correct chemical formula for common salt, sodium chloride, is NaCl.