Properties of Matter and Solutions Slide 3 / 142 Slide 4 / 142 - PDF document

Slide 1 / 142 Slide 2 / 142 Properties of Matter and Solutions Slide 3 / 142 Slide 4 / 142 Matter Properties of Matter and Solutions We define matter as anything that has mass and takes up space. Pyrite, otherwise known as "fools gold" has fooled many a tourist over the years. Physical and Molecules of a Atoms of an element compound chemical properties such as density or reactivity help us identify what substances are made of. Mixture of elements molecules of a and a compound diatomic element Slide 5 / 142 Slide 6 / 142 What is Matter Made of? Elements Elements and Compounds Elements are found on the periodic table. Substances that could not be broken down by any physical or chemical method were/are called elements Substances that could be broken down into different elements using physical or chemical methods were/are called compounds Element Compound Mg-Magnesium Ne(g) CO 2 (g) Cu-Copper Ca(s) CaCO 3 (s) Au(s) AuNO 3 (s) Hg(l) HgI(s) Al I-Iodine vapor Na Aluminum foil Sodium C-carbon diamond and graphite

Slide 7 / 142 Slide 8 / 142 1 Which of the following would NOT be a Compounds compound? Compounds are formed by combinations of different A HCl types of elements. B CS 2 C H 2 O D CH 4 E I 2 CAFFEINE Slide 9 / 142 Slide 10 / 142 2 Which of the following is FALSE regarding Law of Definite Composition compounds? When electricity is passed through water (a compound), hydrogen A They consist of more than one element combined and oxygen gas are produced. B A compound has a set of properties distinct from the individual elements from which it is made electricity When a compound is separated into its elements, liquid water ------------> hydrogen gas + oxygen gas the elements will have the same properties of the C 100 grams 11.2 grams 88.8 grams compound When the amounts of gases produced are analyzed, D Br 2 would not be considered a compound no matter where the water came from or how large the sample, water always consists of exactly 11.2% hydrogen and E NaCl would be considered a compound 88.8% oxygen by mass. Slide 11 / 142 Slide 12 / 142 Pure Substances vs. Mixtures Law of Definite Composition Some matter can be separated by heat, filtering, or boiling into other substances but did NOT obey the law of definite composition. These substances are known as mixtures and are In fact, each compound had it's own definite composition by mass. NOT pure substances. More on mixtures later! % carbon by % oxygen by Pure Substance Mixture Substance mass mass Definitive Composition Non-definitive composition carbon dioxide 27.3% 72.7% Examples: Examples: steel (Fe, C, Mn, Cr, ...) gold (Au) carbon monoxide 42.8% 57.1% This principle, that a certain substance will have it's salt water (H 2 O, Cl-, Na + , ...) pure water (H 2 O) own unique set composition of elements, is known as the Law of Definite Composition.

Slide 13 / 142 Slide 14 / 142 3 A sample of material A is collected in Nevada and 4 A sample of a material is found to contain 56% found to consist of 94% oxygen and 6% hydrogen by oxygen, 32% iron, and 12% sulfur. When another mass. Another sample of material A is collected in sample of the same material is collected, the Maine and found to contain 94% oxygen and 6% composition was 44% oxygen, 30% iron, and 25% hydrogen. What kind of substance is this? sulfur. What kind of substance is this? A element A Element B compound B Compound C mixture C Mixture D pure substance D B and C E B and D E A, B, and C Slide 15 / 142 Slide 16 / 142 Properties of Matter Physical Properties of Matter It was clear, even to the ancients, that not all matter shares the same characteristics/properties. A physical property is a characteristic that can be observed Substance Property WITHOUT altering the identity of the material. lustrous, soft metal, non-reactive, gold solid at room temperature Physical Properties of water transparent, liquid at room salt water temperature, could be separated by water melts at 0 Celsius at standard pressure heat, no definite composition water is transparent water has a density of roughly 1 g/mL at 25 C transparent, liquid at room pure water temperature, definite composition, water is not soluble (does not dissolve) in gasoline could be separated by electrolysis water is colorless solid at room temperature, high calcium melting point, non-lustrous, could carbonate Notice all of these properties can be observed without changing the be separated by heat identity of the water - it is still water! Slide 17 / 142 Slide 18 / 142 5 Which of the following IS NOT a physical property? Physical Properties of Matter A copper has a reddish gold color Who doesn't like brick oven pizza! A brick used in an oven is made of a mixture of aluminum oxide and silicon oxide. Think of as many B iron reacts with oxygen to form rust physical properties of a brick that you can. Feel free to use terms like high and low if you don't know an exact number. C table salt dissolves easily in water D silver is an excellent conductor of electricity high density high melting point move for answer E all of theses are physical properties reddish color brittle (break not bend)

Slide 19 / 142 Slide 20 / 142 6 Which of the following IS a physical property? Physical and Chemical Changes A acetone has a density of 0.87 g/mL Physical Changes Chemical Changes B aluminum will burn in air to make aluminum oxide C water can undergo electrolysis and produce hydrogen and oxygen gas Chemical changes Changes in matter result in new that don't change the D Both A and C composition of a substances. substance. Includes combustion, E Both B and C Includes changes of oxidation, state, temperature, decomposition, etc. volume, etc. Slide 21 / 142 Slide 22 / 142 Chemical Properties Chemical Properties These properties can only be observed when we attempt to Color change - marshmallow burning change the identity of the material. There are a few tell tale signs that a chemical change has taken place: Color change Emission of Light - wood burning Emission of Light Precipitate formation Production of gas Slide 23 / 142 Slide 24 / 142 Chemical Properties Chemical Properties Class Discussion Compare the chemical Precipitate formation - solid forming from liquid mixtures properties of a pepperoni pizza with that of the brick oven. + Production of gas - when limestone is heated The pizza will react with the oxygen in the air and burn. The move for answer brick will not burn in the air. heat +

Slide 25 / 142 Slide 26 / 142 7 Which of the following is NOT a chemical 8 All of the following are physical properties property? except….? A Gold's low reactivity with oxygen A Silver tarnishing into silver oxide B Gasoline's inability to dissolve in water B gasoline burning in air C Water melting at 0 C C candle wax burning D Hot knife cutting through ice cream cake D candle wax melting E evaporating water away from salt water E iron rusting Slide 27 / 142 Slide 28 / 142 10 Which of the following are chemical changes? 9 In the following list, only __________ is not an example of a chemical change. 1. rusting of a nail 2. freezing of water A dissolution of a penny in nitric acid B the condensation of water vapor 3. decomposition of water into hydrogen and C a burning candle oxygen gases the formation of polyethylene from ethylene D 4. compression of oxygen gas E the rusting of iron A 2, 3, 4 B 1, 3, 4 C 1, 3 D 1, 2 E 1, 4 Slide 29 / 142 Slide 30 / 142 Properties of Matter Extensive Properties of Matter Application When you cook, cheese can be melted or it can be burned. One These are properties in which the value depends on how much of is a chemical change, the other a physical change. Explain which the material is present. is which and how you knew! Examples The mass of a glass of water is 30 grams. The stick has a length of 12.2 meters burned The helium balloon has a volume of 14.7 liters melted Melting is a physical change because the cheese has not changed - we know this because we see no evidence of a chemical change (no gas, light, precipitate, color change). move for answer However, burning cheese is a chemical change because we clearly see a color change, taste change, production of a gas when you set off the smoke detector!