Solution Chemistry A solution is a homogeneous mixture where one substance dissolves another.

Parts of a Solution §The solvent is the substance that breaks up (or dissolves) the other substance into individual atoms, molecules, or ions. §The solute is the substance that has been broken up or dissolved. §A solution can be concentrated (lots of solute) or dilute (little solute).

Types of Solutions §A gas dissolved in a gas: air §A liquid dissolved in a gas: moist air §A solid dissolved in a gas: smog or smoke §A gas dissolved in a liquid: soda pop §A liquid dissolved in a liquid: vinegar §A solid dissolved in a liquid: sweet tea §A gas dissolved in a solid: charcoal gas mask filter §A liquid dissolved in a solid: dental fillings §A solid dissolved in a solid: 14K gold

Water is SO special! §Ocean water is a solution of many substances: solids, liquids, and gases all dissolved in water. §Your blood and body fluids are water solutions of sugars, ions, and minerals. §Water dissolves so many more things than other solvents that it is called the universal solvent.

What affects how fast solids will dissolve? §Temperature! If you increase temperature, solids will dissolve faster.  Movement! If you stir them, solids will dissolve faster! § Particle size! The smaller the particles, the greater the surface area so the faster they will dissolve.

What affects how much will dissolve? §Solubility of most solids in a liquid increases when you raise the temperature! §Solubility of a gas in a liquid decreases when you raise the temperature! §Gases are also affected by pressure. As you increase the pressure, more gas will dissolve. Soft drinks are canned or bottled under pressure so more CO 2 can be dissolved in the solution.

Suspensions and Colloids §Both suspensions and colloids have bigger particles than solutions. §Suspensions have the largest particles, and they settle out over time. §Colloids have particles smaller than those in suspensions but larger than those in solutions. §Colloids generally don’t settle out and often look clear, like a solution. §Colloids scatter light but solutions don’t.

Acids §Acids are substances that produce extra H + ions when in a water solution. §Acids have a pH less than 7.0. §Acids have a sour taste. §Acids turn blue litmus paper red. §Acids react with metals to form H 2 gas. §Acids may be strong or weak. §Acids react with bases in a neutralization reaction to form a salt and water. §Weak acids are found in many foods. §Many acids have H in their chemical formulas. 1)HCl 2)HNO 3 3)H 2 SO 4

Bases §Bases are substances that produce extra OH - ions when put in a water solution. §Bases have a pH greater than 7.0. §Bases taste bitter. §Bases turn red litmus paper blue. §Bases feel slippery when you touch them and are found in soaps and drain cleaners. §Many bases contain OH - ions in their chemical formulas. 1)NaOH 2)KOH 3)Ca(OH) 2

The pH scale §The pH scale goes from 0 to 14 and tells how acidic or basic a solution is. §Acids have a pH below 7.0 but greater than 0. §The lower the pH, the stronger the acid. §Stomach acid has a pH of 2.0 and weak acids like vinegar or apple juice have a pH above 4.0 but less than 7.0. §Pure water is neutral and has a pH of exactly 7.0. §Bases have a pH above 7.0 but below §The higher the pH, the stronger the base. §Drano has a pH of 12.0 but shampoos have a pH range of 8.0 to 9.0. Strong AcidNeutral Strong Base