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When table salt, or sodium chloride (NaCl), is added to water, it undergoes a process called dissociation. This process is essential in understanding how the dissolved substances behave in a solution.
NaCl is composed of sodium (Na\(^+\)) and chloride (Cl\(^-\)) ions. In solid form, they are held together by ionic bonds. However, when NaCl is dissolved in water, these ionic bonds break due to the interaction with water molecules.
The water molecules, which are polar in nature, attract the oppositely charged ions in NaCl, effectively separating them.

• Sodium ions (Na\(^+\)) are attracted to the oxygen end of water molecules, which is negatively charged.
• Chloride ions (Cl\(^-\)) are attracted to the hydrogen end, which is positively charged.

Thus, in a solution, NaCl dissociates completely into Na\(^+\) and Cl\(^-\) ions. In stoichiometric terms, for every mole of NaCl added to the solution, one mole of Na\(^+\) ions and one mole of Cl\(^-\) ions are released. This makes the number of Na\(^+\) ions equivalent to the amount of dissolved NaCl.

Density is a fundamental property of a solution, defined as the mass of the solution per unit volume. It is often expressed in grams per milliliter (g/mL). Understanding solution density helps in determining other properties such as concentration.
In this context, the given solution has a density of 1.03 g/mL. This means that every milliliter of this solution has a mass of 1.03 grams. Knowing this density is instrumental in calculating other quantities, such as the volume of the solution from a given mass, or vice versa.
For instance, if you have a specific mass of the solution, you can determine the corresponding volume using the formula: \[ \text{Volume} = \frac{\text{Mass}}{\text{Density}}\] This relationship is particularly useful when preparing or analyzing solutions, as it provides a direct way to convert between mass and volume, helping in accurate calculations of concentration and molarity.

The concept of a mole is central to chemistry, acting as a bridge between the mass of a substance and its amount in terms of particles, such as atoms or molecules. One mole consists of approximately 6.022 x 10\(^{23}\) particles, known as Avogadro's number.
To calculate the number of moles from a given mass, you use the formula: \[ \text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}\] In the context of the original problem, with NaCl having a molar mass of 58.44 g/mol, you can determine how many moles are present in a given mass of the compound.

• For example, if you have 5.6 g of NaCl, the number of moles is calculated as: \(\frac{5.6\, \text{g}}{58.44\, \text{g/mol}} = 0.0959\, \text{mol}\).

By understanding how to calculate moles, you can determine concentrations, which are expressed in terms of molarity (moles per liter) in solutions. This is crucial in various chemical calculations and practical applications, from laboratory experiments to industrial chemical processes.