Question

Sodium reacts chemically with chlorine to form sodium chloride. Is sodium chloride a mixture or a compound?

Short answer

Sodium chloride (NaCl) is formed when sodium (Na) reacts with chlorine (Cl) through an ionic bond, resulting in unique properties different from its individual elements. Therefore, sodium chloride is a compound, not a mixture.

Step-by-step solution

Define Mixtures and Compounds

A mixture is a material composed of two or more substances that are physically combined but not chemically combined, meaning that they retain their individual properties. Examples of mixtures include sand and salt, or air (composed of nitrogen, oxygen, and many other gases). A compound, on the other hand, is a substance formed when two or more elements are chemically bonded together. This chemical bond results in the substance having unique properties that are different from the individual elements. Examples of compounds include water (H2O) and carbon dioxide (CO2).

Sodium and Chlorine Reaction

When sodium (Na) reacts with chlorine (Cl), it forms sodium chloride (NaCl). The reaction can be represented by the following chemical equation: \( 2Na + Cl_{2} \rightarrow 2NaCl \)

Identify if Sodium Chloride is a Mixture or a Compound

In the reaction between sodium and chlorine, an ionic bond is formed when sodium loses one electron and transfers it to chlorine. This results in the formation of positively charged sodium ion (Na+) and negatively charged chloride ion (Cl-). The electrostatic attraction between these oppositely charged ions forms a strong bond, and it results in a compound called sodium chloride, with unique properties different from sodium and chlorine. So, sodium chloride is a compound, not a mixture.

Key concepts

Ionic Bonding

Ionic bonding is a type of chemical bond where atoms transfer electrons to achieve stability. This results in a formation of ions, with one atom becoming positively charged, known as a cation, and the other becoming negatively charged, known as an anion. This happens because when atoms lose or gain electrons, their balance of protons and electrons is disturbed, leading to charged particles.

The attraction between these oppositely charged ions creates a strong bond called an ionic bond. This bond is typical in compounds formed from metal and non-metal elements. Metals, such as sodium, tend to lose electrons and become cations, while non-metals, like chlorine, gain electrons to form anions.

• Cations - positively charged ions
• Anions - negatively charged ions
• Ionic bonds - strong electrostatic forces of attraction between oppositely charged ions

Ionic compounds, therefore, have distinct properties such as high melting and boiling points due to the strong ionic bonds. They often form crystalline structures.

Sodium Chloride

Sodium chloride, commonly known as table salt, is a classic example of an ionic compound. It forms when sodium (Na), a metal, reacts with chlorine (Cl), a non-metal. The resulting compound, NaCl, has entirely different properties from either sodium or chlorine.

Upon reaction, sodium atoms lose one electron each to become sodium ions ( Na^{+} ), while chlorine atoms gain one electron to become chloride ions ( Cl^{-} ). This transfer of electrons fulfills the octet rule, allowing both ions to achieve stable electron configurations similar to noble gases.

• Na (sodium) + Cl (chlorine) → NaCl (sodium chloride)
• Electrostatic attraction binds Na+ and Cl-
• Forms a crystalline lattice structure

Sodium chloride's crystalline structure makes it stable and solid at room temperature. It is also soluble in water, and when dissolved, it disassociates into its ions.

Chemical Reactions

Chemical reactions occur when substances interact to form new substances with different properties. These reactions involve rearrangement of atoms, which results in breaking and forming bonds. During a chemical reaction, reactants are transformed into products.

For example, when sodium reacts with chlorine to form sodium chloride, a chemical reaction occurs. The reaction is represented by this balanced equation: \(2Na + Cl_{2} \rightarrow 2NaCl\). Here, sodium and chlorine are the reactants, while sodium chloride is the product.

• Reactants - substances that undergo chemical change
• Products - new substances formed in a reaction
• Balanced equation - ensures mass and charge conservation

Chemical reactions are categorized by the type of change they cause. In the case of sodium and chlorine, it’s a synthesis reaction, where simpler substances combine to form a more complex substance. Understanding chemical reactions helps us predict the properties and behavior of new compounds.