1.01 Understanding Our World with Chemistry Dr. Fred Omega Garces Chemistry 111 Chemistry in Society 1 Understanding our World through Chemistry January 10 Exploring our Water Supply California interconnected water system serves over 30 million people and irrigates over 5,680,000 acres (2,300,000 hectare, 1 ha = 100m2) of farmland. As the world’s largest, most productive, and most controversial water system, it manages over 40,000,000 acre feet (49 km3) of water per year. Map of water storage and delivery facilities as well as major rivers and cities in the state of California 2 Understanding our World through Chemistry January 10 LA Scandal for Water Everyone who lives here should appreciate just how it is that we are able to live in a desert that is drier than Beirut, yet still maintain green lawns and golf courses and have enough running water to serve the population of the 2nd largest metropolis in the whole of the US. Southern California owes its tenuous existence to some spectacular feats of engineering, which bring water in from remote sources hundreds of miles away. Before these were There are 3 main water sources coming into the SoCal serving different geographic regions: constructed, the city of LA was reliant upon the intermittent flows Los Angeles Aqueduct - constructed in 1908-1913 of the Los Angeles river which Colorado Aqueduct - constructed around 1940 effectively limited population California Aqueduct- constructed in the 1970s growth. 3 Understanding our World through Chemistry January 10 Cadillac Desert; Owen’s Valley and Mulholland Cadillac Desert. http://www.youtube.com/watch?v=hkbebOhnCjA Here's a statistic: The State of California consumes more energy pumping water around, than some other states use for their entire energy needs. http://www.climatecentral.org/news/california-drought-water-scarce-increasing-energy-demands-18676 4 Understanding our World through Chemistry January 10 1.01 Matter and its Forms Water crystal Phase change of Matter to take another form 5 Understanding our World through Chemistry January 10 Phases of Matter: Terminology Consider the following: solid-liquid-gas How does this take place ? What type of changes are occurring? Is this process reversible ? 6 Understanding our World through Chemistry January 10 Kinetic Molecular Model - Change of state at the molecular level • Solid - fix neighbors, no translation motion and large attraction between particles. Vibration motion is dominant. • Liquid - random tumbling, large translation but particles still attract each other. • Gas - no attraction for each other and large translation in space. 7 Understanding our World through Chemistry January 10 What is the mechanism that brings about the different forms of matter Intramolecular Forces - Force which keeps molecule together, i.e., bonds. Intermolecular Forces - Attractive force between molecules. Responsible for keeping matter in solid or liquid phase. Invisible forces called Intermolecular Forces 8 Understanding our World through Chemistry January 10 Heating Cooling Curve: (IMF at Play) From Ice to Steam and Vice-versa Stage1 Stage2 Stage3 Stage4 Stage5 6.01 kJ mol 540 cal 4.184 J g g ° 1 cal g o Heat Addition 9 Understanding our World through Chemistry January 10 Matter and its Classification • Classification of matter? – • Elements, – • compound, – • mixture, ... • Each Class of matter can take different forms. Phase Element Compound Homogeneous Mixture Heterogeneous Mixture Solid Diamond Table salt 14 karat gold Beach sand Liquid Mercury Water Gasoline Balsamic dressing Gas Oxygen Methane Air Dust • Distinguishing physical & chemical properties. – Identity of matter retained vs. Identity changed 10 Understanding our World through Chemistry January 10 Classification of Matter 11 Understanding our World through Chemistry January 10 Substances: Compounds and Elements Compounds • Single substance with two or more different element Elemental Compound • Substance with one type of element. 12 Understanding our World through Chemistry January 10 Mixtures Homogeneous Mixtures • Two or more substances that is uniformly mixed Heterogeneous Mixtures • Two or more substances that is not uniformly mixed 13 Understanding our World through Chemistry January 10 Forms of Matter use in World War 1 Tear gas, formally known as The sulfur a lachrymatory agent or mustards, or lachrymator (from lacrima sulphur mustards, meaning "tear" in Latin), is a commonly known as non-lethal chemical weapon mustard gas, are a that stimulates the corneal class of related nerves in the eyes to cause cytotoxic and tears, pain, and even vesicant chemical blindness. Common warfare agents with lachrymators include pepper the ability to form spray (OC gas), CS gas, CR large blisters on gas, CN gas (phenacyl the exposed skin chloride), nonivamide, bromoacetone, xylyl and in the lungs. bromide, syn-propanethial- S-oxide (from onions), and Mace (a branded mixture). 14 Understanding our World through Chemistry January 10 Consider the following: Determining Class of Matter Consider the following forms of matter -Classify each material of matter. Carbon Helium Xenon Nitrogen Tetrathiooxalate , dioxide dioxide Carbon disulfide, monoxide Carbon monosulfide CO 2 He XeO2, O2 & NO Xe C2S4, CS2, CS 15 Understanding our World through Chemistry January 10 Consider the following: Determining Class of Matter Consider the following Substances -Classify each material and state phase of matter. -Come up with separation scheme. -Isolate the elements in water. If all of the above were mixed in one pot. If all are mixed, then the ethanol will mix with water. The sucrose will dissolved in the water. Sand is more dense than the liquid and will sink. Carbon or charcoal is less dense so it will float. Separate the sand from the carbon by decanting the carbon with the liquid. Wash sand with more water to remove and residual carbon. Filter the carbon residue from the liquid with coffee filter. Ethanol Sucrose Charcoal Sand Water Boil the remaining mixture, the ethanol will evaporate first since it has a lower boiling(Sugar) point. Eelctrolysis of CollectCompound the distillate. Element Mixture Compound water separates Compound Liquid Solid Solid Liquid the hydrogen The remaining sugar solution can also be heated, and the water boiled but not to drynessSucrose and oxygen otherwiseC2H remaining5OH sugarC will caramelize.SiO Collect2, CaCO the water3 usingH 2aO cold finger trap. Sugar can be isolated by having the remaining water evaporate. C12H22O11 elements in H2O 16 Understanding our World through Chemistry January 10 Changing Matter • Physical change: Identity Retained – Change in the observable properties without change of substance identity: – Refers to material changing form but not identity. – Example: Phase Change – Physical change of matter in which the identity of the substance is retained. • Chemical change: Identity Changed – Refers to material changing to a completely different type of material, or transformation to a new substance. – This process involves bond breaking and bond forming such that material changes identity. 17 Understanding our World through Chemistry January 10 Physical Vs. Chemical • Sugar dissolving Heating Sugar • Cutting wood Burning wood • Applying glue Nylon synthesis • Melting ice Electrolysis of water Doping glass • Breaking glass 18 Understanding our World through Chemistry January 10 Physical vs. Chemical Nylon synthesis Slime synthesis 19 Understanding our World through Chemistry January 10 Separating Matter to its components •Exploitation of the different properties of a mixture to separate matter. 20 Understanding our World through Chemistry January 10 Separating Matter to its components •Chromatography of ink 21 Understanding our World through Chemistry January 10 Summary The Universe = Matter + Energy Matter = Mixture, compounds and elements. • Mixture can be separated to pure substances by physical means. • Compounds can be separated to elements by chemical means only. • When separating mixtures by physical means, the unique properties of matter is used as the basis of separation. 22 Understanding our World through Chemistry January 10 .