MATTER. Chemistry is the study of matter and the changes that matter undergoes. Matter is anything that has mass and takes up space.

Transcription

1 MATTER Chemistry is the study of matter and the changes that matter undergoes. Matter is anything that has mass and takes up space.

2 Properties of Matter Physical Properties Can be observed without changing a substance into another substance. Describe the physical make-up of the material. Boiling point, density, mass, volume, etc. Chemical Properties Can only be observed when a substance is changed into another substance. Describe how the substance changes into a new substance. Flammability, corrosiveness, reactivity with acid, etc.

3 Properties of Matter Intensive Properties Are independent of the amount of the substance that is present. They depend on the internal make-up of the material. Can be used to distinguish one type of matter from another because each substance is unique for these properties. Density, boiling point, color, etc. Extensive Properties Depend upon the amount of the substance present. Can NOT be used to distinguish one type of matter from another. Mass, volume, energy, etc.

4 Properties of Aluminum Date: Aug. 16 or Aug. 17 Partners: Problem: What characteristics can be used to distinguish extensive properties from intensive properties? What characteristics can be used to distinguish physical properties from chemical properties? Hypothesis: By observing matter using the four sense, taste is excluded, the type of property can be determined. Extensive properties change if the amount of matter changes while intensive properties do not. Physical properties can be determined without changing the identity of the substance while chemical properties can only be determined by changing the material into a new substance.

5 Procedures: 1. Obtain a piece of aluminum foil and measure or observe the indicated property. 2. For each property determine if the property is extensive or intensive. 3. Also determine if the property is chemical or physical. 4. Record all observations on the data table. 5. If the observation is a measurement, make sure to measure to the first digit of uncertainty and record the unit of measurement.

6 Data Table: mass length width temperature color phase magnetism observation Results: Extensive or Intensive Physical or Chemical density 2.70 g/cm 3 flammability reactivity with acid soluble in water

7 Results: Calculations: 1. area 2. volume 3. thickness NO CONCLUSION FOR THIS LAB REPORT!

8 Phase Change in Water: Boiling Water Date: August 23 / August 24 Partners: Problem: What happens to the temperature of a substance as the liquid is heated; and as it then goes through a phase change to become a gas? Hypothesis: As a liquid substance is heated the temperature will continue to increase as the energy from the hot plate is transferred to the molecules in the form of increased kinetic energy. As the liquid phase changes to a gaseous phase the temperature will no longer increase as the energy from the hot plate is now transferred to break the bonds between the molecules not to increase the motion of the molecules.

9 Procedures 1. Add 100 ml of water to a 250 ml beaker. 2. Measure the temperature of the water and record as the zero time reading. 3. Heat the beaker on the hot plate, recording the temperature of the water every minute, until the water has been boiling for at least 10 minutes.

10 Results / Conclusion Data Table: Graph: Conclusion: PARAGRAPH Restate problem and hypothesis. Give SPECIFIC RESULTS and explain how your results support the hypothesis. No Theoretical Discussion / Sources of Error / Questions for this Lab Report!

11 Phase of Matter There are 3 main phases of matter. Solid, Liquid, Gas Plasma is the 4 th phase. Exist in stars. Every substance can be in ANY of the 3 phases at the correct temperature and pressure. Changing temperature, pressure, or both causes a substance to go through a PHASE CHANGE.

12 compressed: particles are as close together as possible definite shape definite volume particles do not move they only vibrate in a fixed position strong bonds between particles Solid

13 compressed: particles are as close together as possible INdefinite shape definite volume particles DO move; slide around each other strong bonds between particles (weaker than solid) Liquids

14 Gases NOT COMPRESSED: particles are VERY FAR APART INdefinite shape INdefinite volume particle move freely inside the container NO BONDS between the particles

15 Plasma high temperature high energy gas SO MUCH ENERGY THAT PARTICLES BECOME IONIZED

16 Phase Changes During a phase change the temperature stays constant because the energy is going to break the intermolecular bonds. When not involved in a phase change the energy goes to increasing the temperature. TEMPERATURE IS A MEASURE OF THE AVERAGE KINETIC ENERGY OF THE MOLECULES. (HOW FAST THE PARTICLES MOVE)

17 Phases Diagrams Phase diagrams show how both temperature and pressure effect the phase of a substance. WATER IN EL PASO boils below 100⁰C because both temperature and pressure effect boiling point. El Paso is at a higher altitude then sea level so our pressure is lower.

18 Changes in Matter Physical Changes These are changes in matter that do not change the composition of a substance. Change one or two physical characteristics only. Changes of state, temperature, volume, etc. Chemical Changes Chemical changes result in new substances. A new substance with new properties is created. Combustion, oxidation, decomposition, etc.

19 Indicators of a Chemical Change Production of Light Production of Heat Production of a Gas Production of a PRECIPITATE: An insoluble solid produced when 2 solutions are mixed. Change in Color (CAREFUL WITH THIS ONE.) PRODUCTION OF A NEW SUBSTANCE WITH NEW PHYSICAL AND CHEMICAL PROPERTIES.

20 Physical Changes and Chemical Reactions Date: Aug. 28 / Aug. 29 Partners: Problem: How can observation made with the four senses be used to distinguish between physical changes and chemical reactions? Hypothesis: In some cases only the temperature, physical state, size of particles, or a color change is observed. These changes are called PHYSICAL CHANGES. In a physical change only a physical property is changed but the identity of the material is unchanged. In other cases different substances with new characteristic properties are formed. Such changes are CHEMICAL REACTIONS. Chemical reactions can be distinguished by the indicators of a chemical reaction.

21 Procedures: Record all observations on your data table. Your observations are made with all four senses: visual, auditory, tactile, and olfactory.

22 1. Put one spoonful of sugar in a dry evaporating dish. Add just enough concentrated sulfuric acid to barely moisten the sugar. CAUTION: SULFURIC ACID IS EXTREMELY CORROSIVE!!! 2. While holding one end of a piece of magnesium ribbon about 3 centimeters long with the crucible tongs, ignite the other end in the Bunsen burner flame. CAUTION: DO NOT LOOK DIRECTLY AT THE MAGNESIUM WHILE IT IS BURNING. 3. Heat a piece of copper strip in the Bunsen burner flame for seconds. 4. Add a small piece of zinc to 5 milliliters of hydrochloric acid in a test tube. When the reaction is proceeding vigorously, test the gas with a burning splint. A bark indicates hydrogen gas production. 5. Fill a 50 ml beaker about ½ full of water. Add one small spoonful of sodium chloride to the beaker and stir. 6. Put a few drops of the solution from procedure #5 on the curved side of a watch glass. Put the watch glass on a beaker half filled with water and place the beaker on a hot plate. Examine the substance on the watch glass after the water vaporizes. 7. Put 2 milliliters of silver nitrate solution in a test tube. Add 2 milliliters of hydrochloric acid to the silver nitrate. 8. Filter off the filtrate (the liquid) from procedure # 7. Fold a piece of filter paper and place the filter paper into a funnel. Put the funnel into a 100 ml graduated cylinder and then pour the contents of the test tube into the funnel. Expose the residue (solid precipitate) to the sunlight. 9. To ½ an Alka-Seltzer tablet in a 50 ml beaker, add 10 ml of water. After 5 seconds hold a burning splint in the lower portion of the beaker.

23 Results: sugar and sulfuric acid burn magnesium heat copper zinc and hydrochloric acid sodium chloride and water vaporize water off sodium chloride silver nitrate and hydrochloric acid expose precipitate to sun light alka seltzer and water visual auditory tactile olfactory

24 Conclusion: Restate the problem and hypothesis and then explain how the observations determined if the change was a physical change or a chemical reaction. Use the indicators of a chemical reaction to justify each chemical reaction. This must be in paragraph form and YOU CAN NOT USE I OR WE.

25 Classification of Matter

26 Heterogeneous Matter Matter that is obviously two or more substances. Can see with the naked eye at least 2 separate substances. A mixture that does not BLEND. Individual substances remain distinct.

27 Homogeneous Matter Matter that appears to be one substance to the NAKED EYE. A mixture that has constant properties.

28 Classification of Matter Main types of Matter: ELEMENTS COMPOUNDS MIXTURES SOLUTIONS

29 MIXTURE A PHYSICAL combination of 2 or more substances. Can be created with any proportion of the substances. Components keep their own properties. Can be separated by PHYSICAL means. FILTRATION: physical separation of solid and liquid using a porous barrier.

30 SOLUTION A PHYSCIAL combination of two or more substances where one substance DISSOLVES in the other. Can be in any proportions. Each component keeps its own properties. The particles dissolve so they are harder to separate than a regular mixture. DISTILLATION: physical separation based on differences in boiling points. CHROMOTOGRAPHY: separation by dissolving in a liquid or a gas. Each component travels at a different rate based on physical differences.

31 COMPOUND A CHEMICAL combination of 2 or more elements. The ratio of the elements is FIXED AND CAN NEVER CHANGE. H 2 O: 2 hydrogen to 1 oxygen. The elements LOSE THEIR PROPERTIES and take on completely new properties. Can only be separated by a chemical reaction. TYPES: Ionic or Covalent Inorganic or Organic

32 ELEMENT The simplest form of matter. Can NOT be separated into simpler substance by physical or chemical means. Is the building block for ALL other types of matter. The atom can only be changed by a NUCLEAR REACTION. TYPES: Metal or Nonmetals or Metalloids Naturally Occurring or Man Made.

33 Classification of Matter / Iron and Sulfur Date: September 6 / September 7 Partners: Problem: Are the properties of the elements that make a compound and a mixture the same as the properties of the elements? Hypothesis: The properties of the elements stay the same for a mixture because a mixture is a physical combination of the elements. However, the properties of the elements are different than the properties of the compound because a compound is a chemical combination of the elements so a new substance with new properties is created.

34 Classification of Matter / Iron and Sulfur Procedures: 1. Make observation on the properties of: iron sulfur an iron sulfur mixture an iron sulfur compound (iron II sulfide) 2. Observations: -color -magnetism -reaction with hydrochloric acid -any other property of your choice

35 Classification of Matter / Iron and Sulfur Results: Create a data table showing all properties. Chemical Reactions: Fe (s) + S (s) FeS (s) Fe (s) + 2 HCl (aq) FeCl 2(aq) + H 2(g) S (s) + HCl (aq) N.R. FeS (s) + 2HCl (aq) FeCl 2(aq) + H 2 S (g) Conclusion: Restate PROBLEM AND HYPOTHESIS. Give SPECIFIC RESULTS FROM EXPERIMENT and explain how these results support the hypothesis.

36 Matter Exam Properties of Matter Physical vs. Chemical Extensive vs. Intensive Phases of Matter Solid, Liquid, Gas, Plasma Phase changes Phase change graph Changes in Matter Physical vs. Chemical Indicators of a Chemical Reaction Classification of Matter Homogeneous vs. Heterogeneous Elements, Compounds, Mixtures, Solutions Measurement Conversions Dimensional Analysis: 4 steps What: 24 cm = m How: 1 m = 100 cm Do IT: 24 cm x Answer: =0.24 m Temperature Conversions. Know how to use formulas.