Nature of Solutions Quiz

Nature of Solutions

• A solution is a homogeneous mixture of two or more substances, where one substance is dissolved in another.
• Solute is the substance being dissolved, while solvent is the substance that does the dissolving.
• Particles of dissolved solute are ionic or in molecular form, with sizes ranging from 10-8 to 10-7cm.
• Water is called the "universal solvent" and solutions with water as the solvent are called aqueous solutions.

Properties of Solutions

• Solutions are homogeneous mixtures of two or more components, with variable composition.
• Solute particles are uniformly distributed throughout the solution and will not settle out with time.

Types of Solutions

• Gas solutions: mixture of two or more different gases.
• Liquid solutions: solids, liquids, or gases dissolved in liquid.
• Solid solutions: solutions of two or more metals, also known as alloys.

Examples of Solutions

• Gas solutions: air (oxygen in nitrogen).
• Liquid solutions: softdrinks (CO2 in water), ethylene glycol in water, vinegar in water, and alcohol in water.
• Solid solutions: seawater, naphthalene in kerosene, brass (Cu in Zn), sterling silver (Cu in Ag), bronze (Cu in Sn), and 18 karat gold (Cu and Ag in Au).

The Dissolving Process

• The process of a solute mixing with a solvent to produce a solution is called dissolving.
• Solubility is the maximum amount of a solute that will dissolve in a given quantity of solvent at a specific temperature.

Solubility

• A solution that contains the maximum amount of a solute in a given solvent at a specific temperature is called a saturated solution.
• A solution that contains less solute than it has the capacity to dissolve is called an unsaturated solution.
• A supersaturated solution contains more solute than is present in a saturated solution and is very unstable.

Factors that Affect Solubility

• Nature of solute and solvent: "Like dissolves like".
• Temperature: increasing temperature increases the solubility of solids in a liquid, but decreases the solubility of gases in a liquid.
• Pressure: has no influence on the solubility of liquids and solids, but greatly affects the solubility of gases, as stated by Henry's law.

Factors Affecting the Rate of Solution of Solids in Liquids

• Particle size: smaller particles increase the rate of solution.
• Stirring: increases the rate of solution.
• Heating: increases the rate of solution.

Electrolytes and Nonelectrolytes

• Electrolytes: substances that dissolve in water to form a solution that conducts an electric current.
• Strong electrolytes: completely dissociate in water, such as HCl, HNO3, and NaOH.
• Weak electrolytes: partially dissociate in water, such as H2CO3, and NH3.
• Nonelectrolytes: substances that do not conduct an electric current, such as C6H12O6 (glucose), and C12H22O11 (sugar).

Concentration of Solutions

• It is a measure of the amount of solute dissolved in a given amount of solvent.
• A solution can be described as dilute or concentrated.