# What is a solution? Usually a Homogeneous Mixture of two or more substances in a physical state Made of two parts Solute Solute: part being dissolved.

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What is a solution? Usually a Homogeneous Mixture of two or more substances in a physical state Made of two parts Solute Solute: part being dissolved Solvent Solvent: part that does the dissolving

Example of a solution Salt + water → saltwater Which is the solute? salt Which is the solvent? water

What is a precipitate? The solid that forms from a solution.

What is an aqueous solution? A solution where the solvent is water

Can a Heterozygous Mixture form a solution? Yes, but it is usually considered a temporary solution Suspension: has different parts that settle to the bottom (Example dirt and water mixed)

What is a Colloid? A stable Heterozygous Mixture that forms a solution The particles don’t settle out Why? The particles are electrically charged and repel each other to form bigger particles Example: Milk

What is Concentration? The ratio of a solute to solvent Example: 95% water to 5% salt

Concentration formulas M (Molarity)=mole of solute ٪ Liter of solution m (Molality)= mole of solute ٪ Kilograms of solution ppm (Parts per million) 1 st step: grams of solute x1,000,000g of solution 2 nd step: Divide answer by grams of solvent

Concentration formulas cont. Mole Fraction X A =n A ٪ n A +n B X B = n B ٪ n A + n B n A =number of moles of solvent n B =number of moles of solute

Solubility “Oil and Water don’t mix” The reason is oil is nonpolar and water is polar Solubility- is the ability of one substance to be dissolved into another substance at a given temperature and pressure  Polar substances dissolve (break down) other polar substances  Nonpolar dissolves Nonpolar  Examples are cleaning products that take stains out of clothes  Water soluble vitamins (B and C)or oil soluble vitamins (A, D, E, K)

Miscible vs. Immiscible Liquids that totally dissolves one another are miscible (Ex. polar to polar or additional electrical force pulling them together) Immiscible are insoluble liquids-so they form layers

What affects solubility rate? The greater the surface area the faster something will dissolve Increase in temperature usually increases the solubility of solids Enthalpy and Entropy increase the ability for salts to dissolve (dissociation-breaks down a salt into its individual parts)

Soluble vs. Insoluble Soluble-will dissolve Insoluble-won’t dissolve

Saturation Saturated solution-the maximum amount of solute is in a solution Unsaturated solution-means more solute can be added Supersaturated solution-More than normal amount of solute is added and dissolved than normal due to increased heat or pressure

Henry’s Law The law states that at constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas on the surface of the liquid

Physical Properties of Solutions Conductivity of a substance depends on whether it contains charged particles, and these particles must be able to move (electrons) Electrolytes are substances that dissolve in a liquid solvent and provide ions that conduct electricity (like Na+ and Cl-) Nonelectrolytes do not conduct electricity when put in a liquid solvent (like sugar-does not ionize because it is covalent) Acids react with water to form hydronium ions (H 3 O+) Tap Water and Sea Water conducts electricity

Colligative Properties Any Physical properties of a liquid Solubility Melting point Boiling point Boiling-point elevation-being able to increase the boiling point Ex.: Adding salt to water so it won’t boil at normal temperature, adding glycol in a car’s radiator so it won’t overheat Freezing point Freezing-point depression-being able to melt at a lower temperature Ex.: Adding salt to an icy sidewalk

Surfactants Are compounds that concentrate at boundary surface between two immiscible phases (solid-liquid, liquid to liquid, or liquid –gas) Types 1. Detergent-a water-soluble cleaning agent 2. Soap –detergent with an emulsion agent(made of colloid-sized droplets suspended in liquid which are usually insoluble) Without emulsion agents polar and nonpolar molecules remain separate Clean dirt and oil

THE END

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