Solutions Concentration and Solubility Solutions A solution is

Solutions: Concentration and Solubility

Solutions • A solution is a homogenous mixture • Can occur as a solid, liquid, or gas • Solid solutions are called alloys • Liquid and gas solutions are simply called solutions

Elements of a Solution • Solutions consist of solutes and solvents Solute – A substance that dissolves Solvent – The substance into which the solute dissolves (usually present in the greatest amount)

Examples of Common Solutions Solute + Solvent = Solution Solute Solvent Solution Zinc (solid) Salt, minerals (solid) Ethylene glycol (liquid) Oxygen, argon (gas) Copper (solid) Water (liquid) Nitrogen (gas) Brass Seawater Antifreeze Air

Identify the solute and the solvent in these solutions: • Carbonated beverage Carbon dioxide Sugar Flavour crystals (solute) Water (solvent) • Salt water Salt (solute) Water (solvent) Solute Solvent

Water -the Universal Solvent • Why? – Many different solids, liquids, and gases dissolve in it to form solutions Are all substances soluble in water? – Not all substances are soluble in water. e. g. many oils and fats do not dissolve in water https: //www. youtube. com/watch? v=Ih. Qtq ou. Ev 1 U

Solubility • The relative ability of a solute to form a solution when added to a certain solvent • In other words, the maximum amount of solute you can dissolve in a fixed amount of solvent at a given temperature

How Are Solutions Formed? • The solute particles must be attracted to the solvent particles, which allows the particles to spread evenly throughout the solution

Does Salt Dissolve in Oil or Water? – Salt dissolves in water because the particles are attracted to one another. Salt particles form clumps and do not dissolve in oil because the particles are not attracted to one another. – When a substance does not dissolve in a solvent, that substance is insoluble in that solvent. – When one of the substances is insoluble in the other, a solution is not formed by the combination of the two substances.

Concentration. Qualitative The amount of solute in a Solvent can be expressed in qualitative terms. Qualitative data: • Deals with descriptions. • Data can be observed but not measured. • Colors, textures, smells, tastes, appearance, beauty, etc. • Qualitative → Quality

Concentration. Qualitative • A concentrated solution is a solution that contains a large amount of dissolved solute and very little solvent. E. g. frozen juice concentrate • Solutions are dilute when very little solute is dissolved in the solvent. E. g. by adding water to the frozen juice concentrate, you would be diluting the frozen juice.

Concentration. Quantitative The amount of solute in a Solvent can be expressed in quantitative terms. Quantitative Data • Deals with numbers. • Data which can be measured. • Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc. • Quantitative → Quantity

Concentration. Quantitative • The concentration of a solution is the amount of solute dissolved in a specific amount of solvent. • E. g. if 5 g of salt are dissolved in 500 m. L of water, the concentration is 5 g/500 m. L (or 1 g/100 m. L) or 1% solution.

Saturation • In all solutions, there is a maximum amount of solute that can be dissolved in a given amount of solvent at a given temperature. This is called saturation. • A solution is saturated when it has been formed from the maximum amount of solute for a given amount of solvent at a certain temperature.

Saturation point – No more solute can be dissolved in a fixed volume of solvent at a given temperature Unsaturated – More solute can be dissolved in a solvent at a given temperature Supersaturated – Under certain circumstances, a saturated solution can be cooled below a critical temperature to form a supersaturated solution, which contains more solute than would normally be dissolved in the solution.

• http: //videos. howstuffworks. com/hsw /17089 -physical-science-solubilityvideo. htm

Check and Reflect 1. Explain how to change a dilute solution to a concentrated solution. 2. Explain the meaning of the terms saturated and unsaturated. 3. Think back to the lab “Making a Solution” using drinking crystals and water. a) Identify the solvent and the solute b) When was the solution saturated, unsaturated and what was the saturation point?