solutions (introduction & classifications)

SolutionsSolutions

SolutionsSolutions

SolutionsSolutions

Definition

• A homogeneous mixture of two or more substances

• Uniform in composition and properties

Components

• Solutes– Dissolved substances– Substance present in smaller quantity

• Solvents– Dissolving medium– Substance present in greater quantity

Test your knowledge…

Identify the solute and solvent in the following solutions:

• Potassium chloride (KCl crystals) and water

• 10cm3 acetone + 20 cm3 alcohol• 75% nitrogen gas + 25% oxygen

gas

Types

• Properties• Concentration• Ability to conduct electric current

Classification according to phase

liquidliquid

solidsolid gaseousgaseous

Classification according to Concentrations

• Saturated solutions– A solution which

contains, at a specific temperature, an amount of solute that it can normally hold in the presence of a given amount of solvent.

Classification according to Concentrations

• Unsaturated solutions– A solution which

contains less amount of solute that it can normally hold

Classification according to Concentrations

• Supersaturated solutions– A solution which

contains more solute than what it can normally hold

• Laboratory terms– Dilute

• Solutions which contains small quantity of solute relative to the solvent

– Concentrated• Solutions which contains large amounts of

solute compared to the amount of solvent present

Classification according to Concentrations

Classification according to Electrical Conductivity

• Electrolytes– Solutions that conduct electricity– Substances that are ions in solution– Cations (K+, Na+, Mg2+, Ca2+) & anions

(Cl-, CO32-)

• Non-electrolytes– Solutions that do not conduct electricity

 Strong electrolyte Weak

electrolyte Non-electrolyte

 Sea water  Tap water Chemically pure

water

 Hydrochloric acid  Carbonic acid  Alcohol

 Sulphuric acid  Acetic acid  Kerosene

 Aqueous copper sulphate

 Ammonium hydroxide

 Aqueous sugar solution

 Molten lead bromide  Citric acid  Carbon disulphide

 Aqueous sodium chloride

 Oxalic acid  

 Nitric acid    

 Aqueous potassium hydroxide

Examples of Electrolytes

A simple set-up of a

conductivity apparatus