material organization.notebook September 09, 2016

Transcription

1 Organization of Matter 1

2 Review: CPs and NCPs Non Characteristic Properties: A physical or chemical property that is NOT UNIQUE to one particular substance Characteristic Properties: A physical or chemical property that IS UNIQUE to a particular substance 2

3 Characteristic or Non Characteristic CP NCP Magnetism Melting Point Density Boiling Point Solubility Shape Mass Volume Colour Temperature 3

4 Review: Organization of Matter Vocabulary Atom smallest unit that makes up matter Element substance made from one type of atom Molecule group of atoms that are chemically bonded Pure Substance only one type of particle Compound pure substance formed by combining two or more different atoms Mixture two or more substances that are NOT chemically combined Heterogeneous Mixture mixture with visible differences Homogeneous Mixture mixture with no visible difference Solution homogeneous mixture, impossible to distinguish under magnification Colloid homogeneous mixture, distinguishable under magnification 4

5 Matter Pure Substances Mixtures Elements Compounds Heterogeneous Homogeneous Colloid Solution 5

6 Identifying Substances in the Lab Often we are asked to identify various substances in the lab based on their physical or chemical properties Specifically, we are able to identify them by testing for the presence of characteristic properties 6

7 Tests for Identification Substance Test Reaction Electroconductivity Conductivity Meter if the substance can conduct electricity, the conductivity meter will light up when the prongs are places on the substance substances can be weak, medium or strong conductors Presence of H 2 O Cobalt Chloride Paper (CCP) when the ccp strip is placed in the substance it will turn from dark blue to light pink ph level Red Litmus Paper (RLP) Blue Litmus Paper (BLP) if the substance is acidic, the BLP will turn red if the substance is basic the RLP will turn blue a neutral substance will not cause either to change Presence of Glucose Glucose Test Paper If the substance contains carbohydrates (glucose), the glucose test paper will turn from yellow to green when placed in the substance Presence of Protein Protein Test Solution when the two solutions are combined, and the substance added, the solution will begin to turn violet around the edges if protein is present Presence of Fat Alcohol Test when alcohol is added to the solution, it will turn cloudy and white if fat is present Presence of H 2 Gas Lit Split Test when a lit splint (burning) is placed in the presence of H 2 gas, a "popping" sound will be heard Presence of O 2 Gas Glowing Splint Test when a glowing splint (glowing embers) is placed in the presence of O 2 gas the splint will re ignite Presence of CO 2 Gas Lime water Test when lime water, Ca(OH) 2 is added to CO 2 gas, the liquid becomes cloudy/milky 7

8 Review: Changes to Matter Physical Change: appearance of the substance is changed but not the nature of the substance Chemical Change: two or more substances (reactants) react with each other to produce a new product. This product is chemically different than either of the reactants. 8

9 Signs of a Chemical Change 1) Change in colour 2) Formation of a gas (bubbles in a liquid, or the presence of "smoke") 3) Formation of a precipitate (when two liquids are mixed and a solid forms, which settles to the bottom) 4) Variation in heat (gets warmer or cooler) 5) Emits a light 9

10 Types of Chemical Changes To represent a chemical transformation we use equations + A B AB The substances on the left are the reactants, and on the right are the products 10

11 Synthesis Reaction Two or more substances COMBINE to produce a new substance + A B AB The resulting product has a greater mass than either of the reactants individually EXAMPLES: 2H 2 + O 2 > 2H 2 O Hydrogen + Oxygen > Water Cl 2 + 2Na > 2NaCl Chlorine + Sodium > Sodium Chloride (table salt) Burning Magnesium 11

12 Decomposition Reaction A compound is broken down into 2 or more substances + AB A B The resulting products have a lower mass (individually) than the initial reactant EXAMPLES: 2H 2 O > 2H 2 + O 2 Water > Hydrogen + Oxygen 2NaHCO 3 > Na 2 CO 3 + CO 2 + H 2 O Sodium Bicarbonate (Baking Soda) > Sodium Carbonate + Carbon Dioxide + Water Decomposition of Hydrogen Peroxide (H2O2) 12

13 Oxidation Reaction Occurs when a substance combines with one or more atoms of oxygen The resulting substance is an OXIDE Oxidation reactions are synthesis reactions that involve oxygen EXAMPLES: 4Fe + 3O 2 > Fe 2 O 3 Iron + Oxygen > Iron oxide (rust) C 6 H 12 O 6 + 6O 2 > 6CO 2 + 6H 2 O + Energy Glucose (sugar) + Oxygen > Carbon Dioxide + Water Oxidizing Glucose (Gummy Bear Sacrifice) 13

14 Precipitation Reaction Occurs when two substances in solution combine to form a new substance that is insoluble in the solution Insoluble: incapable of being dissolved This insoluble substance is called the precipitate EXAMPLE: Pb(NO 3 ) 2 (aq) + 2KI (aq) > PbI 2 (s) + 2KNO 3 (aq) Lead (II) Nitrate + Potassium Iodide > Lead (II) Iodide + Potassium Nitrate Precipitation for Relaxation 14

15 Attachments Burning Magnesium Decomposition of Hydrogen Peroxide H2O2 Oxidizing Glucose Gummy Bear Sacrifice Precipitation for Relaxation