Mixtures and Solutions UNIT 5

a.What is a Homogeneous Mixture? b.What is a Heterogeneous Mixture? I. REVIEW

a.A solution is a mixture containing a solvent and at least one solute b.A solvent is the substance doing the dissolving c.A Solute is the substance being dissolved d.Water is known as a “universal solvent” because it dissolves so many substances i. Water is the solvent for plant nutrients in soil as well as our own blood, sweat, and tears. II. SOLUTIONS

III. FORMING A SOLUTION

a.Dilute Solution: very little solute b.Concentrated Solution: a lot of solute but it is not overwhelming the solution c.Saturated Solution: There is so much solute the solvent cannot dissolve it all d.Things that effect the amount of solubility are: pressure, type of solvent, and temperature IV. FACTORS OF SOLUBILITY

Chemical Reactions UNIT 6

a.These can be described as Physical and Chemical Changes b.A Physical Change i. A change that alters the form or appearance of a substance. However, it does not change into another substance ii. The physical properties are changed but the chemical make-up does not change iii. Does not require a chemical reaction to occur iv. Examples: Crushing, melting, freezing, and boiling I. CHANGES IN MATTER

c. A Chemical Change i. A change in the chemical composition of a substance ii. This occurs through a chemical reaction iii. When undergoing a chemical change, the physical properties of the substance will also change iv. The substance that is chemically changing is called the reactants v. The new substance that is formed is called the products I. CHANGES IN MATTER

a.The Law of Conservation of Mass says that Matter cannot be created or destroyed b.The matter that is around in any chemical reaction just changes form c.Example: Methane (______) + Oxygen (_____) II. CONSERVATION OF MASS

a.A chemical change will always result in a new substance b.Two different types of Chemical reactions i. Exothermic Reaction: Energy is released from the reaction, usually in the form of heat 1. Example: Oxygen and fuel-producing fire ii. Endothermic Reaction: Energy is taken in or absorbed, causing the reaction to feel cold 1. Example: Baking soda and vinegar III. RECOGNIZING A CHEMICAL CHANGE

c. Changes in Properties i. You can recognize a chemical change by noticing physical changes 1. Formation of a precipitate: a solid that forms from liquids during a chemical reaction 2. Color Change can indicate that a new substance was formed 3. Gas formation, often seen as bubbles III. RECOGNIZING A CHEMICAL CHANGE

a.Use a chemical equation i. Always use the chemical formula for the reactants and products ii. Put the reactants on the left side of the equation iii. Put the products on the right side of the equation iv. Do not use an equal sign but instead an arrow between the reactants and products v. The number of each type of atom must be the same on both side of the equation 1. Example: Reactant + Reactant Product+Product IV. DESCRIBING A CHEMICAL REACTION

2. Example: IV. DESCRIBING A CHEMICAL REACTION

Balance Each Equation. 1. C 3 H 8 + O 2  CO 2 + H 2 O 2. Al + Fe 3 N 2  AlN + Fe 3. KNO 3 + H 2 PO 4  K 2 CO 3 + HNO 3 4. ZnS + AlP  Zn 3 P 2 + Al 2 S 3 5. H 2 O + CO 2  C 7 H 8 + O 2 WARM-UP #1

Balance These Equations. Use the Reactants/Products box we used last week to help. 1. Na 2 SO 4 + CaCl 2  CaSO 4 + NaCl 2. C 2 H 6 + O 2  CO 2 + H 2 O 3. Cu 2 O + C  Cu + CO 2 WARM-UP #2

a.Chemical Reactions need a “push” to help them start i. This “push” is called Activation Energy ii. Each chemical reaction has a given amount of Activation Energy it need to start iii. Visual iv. Example: Hydrogen and Oxygen 1. To create water, if you put the two gases together, nothing happens, but if you add a little bit of heat, the molecules will combine due to that activation energy. VI. CONTROLLING A CHEMICAL REACTION

b. Factors that affect Rate of Reaction i. Surface Area: smaller pieces means that the reactions can happen faster ii. Temperature: when reactions are given heat their molecules move faster allowing for the reaction time to increase iii. Concentration: Increasing the amount of reactant molecules allows for a quicker reaction due to the fact that there are now more particles to react with each other VI. CONTROLLING A CHEMICAL REACTION

iv. Catalyst: increases the reaction rate by lowering the activation energy needed 1. Enzymes: special biological catalyst to help increase reaction rate at body temperature v. Inhibitor: decreases reaction rate VI. CONTROLLING A CHEMICAL REACTION

vi. Reaction in the presence of a catalyst vs. an inhibitor 1. Catalyst VI. CONTROLLING A CHEMICAL REACTION

2. Inhibitor VI. CONTROLLING A CHEMICAL REACTION