CHEM 1212 Important Equations Midterm Dalton s Law of Partial Pressures States that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture PTotal P1 P2 P3 Ideal Gas Law The state of an amount of gas is determined by its pressure volume and temperature The state of an amount of gas is determined by its pressure volume and temperature Where P is the absolute pressure of the gas atm V is the volume L N is the number of particles in the gas k is Boltzmann s constant relating temperature and energy 0 08206 and T is the absolute temperature Kelvin PV nRT Beer s Law Absorbance Slope constant x Concentration Lab Safety Irritant Do not breathe vapors Avoid contact with skin and eyes Corrosive Wear safety goggles Avoid contact with skin eyes or clothing Flammable Keep chemical away from heat sparks or flames Keep container closed Oxidizing Agent Keep chemical away from contact with skin eyes or clothing Avoid mixing with other chemicals except as directed Toxic Avoid all contact with the body Avoid inhalation swallowing or contact with skin especially Lachrymator cause tears Open bottle in the fume hood Avoid contact with eyes and skin Carcinogen cancer causing Use extreme care when using or handling Avoid all contact with skin eyes Hygroscopic absorbs H2O Keep container tightly capped Recap immediately after use Moisture Sensitive Keep container tightly capped Recap immediately after use Do not let chemical sit broken skin lungs out in the air 1 PPE personal protective equipment 2 3 things to wear at all times apron closed toe shoes goggles Lab 1 Physical and Chemical Properties Ex color melting point density 1 Physical properties attributes and characteristics that describe what the chemical species is 2 Chemical properties attributes and characteristics that depend on how a chemical species reacts 3 Miscibility ability of two liquids to completely mix with each other liquid dissolving in another liquid Ex alcohol and water mix completely they are miscible with each other Ex solubility miscibility chemical reactivity 1 8 Ex oil and water form layers when mixed so they are immiscible with each other Ex sugar is soluble in water but sand is insoluble in water Ex Carbon dioxide g dissolves in water slightly soluble to form carbonated beverages 4 Immiscible characteristic of liquids which do not mix with each other liquids will form 2 layers when combined 5 Solubility ability of a gas or solid to dissolve in a liquid 6 Solvent solution that does the dissolving present in greater amount 7 Solute substance that is dissolved present in lesser amount 8 Meniscus curvature of a liquid in a column due to intermolecular forces between the liquid and the walls of the container 9 The layer with the lesser density will float or rise to the top of the denser liquid In an oil water mixture the less dense oil will float on top of the more dense water Lab 2 Synthesis of Potassium Alum 1 Alums a class of double salts with the formula of MAl SO4 2 x 12H2O where M alkali metal cation Ex Potassium alum Kal SO4 2 x 12H2O is found in grocery stores alum is used for pickling and in industry it is used in waste water treatment and in the production of paper 2 Theoretical yield in theory the amount of product that could be produced if the reaction were 100 efficient 3 Actual yield actual amount of product recovered in the experiment 4 Percent yield ratio of the actual yield to the theoretical yield multiplied by 100 5 Aluminum foil is limiting reagent in calculations Lab 3 Copper Cycle Combination A B AB Decomposition AD A D Single Displacement AC B AB C Double Displacement AC BD AD BC Oxidation Reduction A B A n B m 1 Types of Reaction 2 In Oxidation Reduction metathesis reaction one species will lose electrons in first oxidation half reaction These electrons are used in the reduction half reaction where the second species gains the electrons Lab 4 Citric Acid in Fruit Juices 1 Titration technique to determine how much analyte is present in a sample by reacting analyte with a known amount of titrant 2 Analyte species being analyzed 2 8 3 Titrant species added in small increments by a buret 4 Indicator used to determine the end of reaction by changing colors 5 Endpoint end of the reaction noted by change of colors for the indicator 6 In this experiment the citric acid is analyte NaOH is the titrant and phenolphthalein is the indicator colorless at acidic pH pink at basic 7 In this experiment to estimate the amount of citric acid analyte in fruit juices you will add NaOH titrant to the fruit juice until the solution with the phenolphthalein indicator changes color to pink Since some of the juices are colored the endpoint maybe a slightly different color H3C6H5O7 aq 3 NaOH aq Na3C6H5O7 aq 3 H2O l mol NaOH M NaOH LNaOH mol H3C6H5O7 mol NaOH 1 mol H3C6H5O7 3 mol NaOH mass H3C6H5O7 mol H3C6H5O7 MW H3C6H5O7 mass H3C6H5O7 mLjuice mass H3C6H5O7 mLjuice Lab 5 Vitamin C in Fruit Juices 1 DRI Daily Recommended Intake of Vitamin C for adults 2 Standardization determining the concentration of the titrant using a known amount of a standard DCP 3 Aliquot portion of a larger sample 4 The ascorbic acid in fruit juice is the analyte DCP is the titrant and its own indicator ascorbic acid alone is used to make the standard in volumetric flask 5 DRI is 90 mg per day however National Institute of Health recommends 200 mg per day Another study suggests 6 000 12 000 mg per day 6 Find Molarity of the ascorbic acid solution DCP is deep blue initially colorless after it reacts and red in acidic solutions Use the mass of C6H8O6 molar mass molecular weight and the total volume of solution to calculate the M of the standard C6H8O6 solution M C6H8O6 massC6H8O6 x 1 mole C6H8O6 176 14 g C6H8O6 x L of soln Find the Molarity of the DCP solution Use the M mL of C6H8O6 and stoichiometry to find moles of DCP Then divide moles of DCP by the L of DCP to find the M of DCP moles DCP M C6H8O6 x L C6H8O6 x 1 mole DCP 1 mole C6H8O6 M of DCP mol DCP L DCP Find the mg of Vitamin C present Use the M mL of DCP stoichiometry and the molar mass molecular weight of C6H8O6 to calculate the mg of C6H8O6 mg C6H8O6 M DCP x L DCP x 1 mol C6H8O6 1 mol DCP x 176 04 g C6H8O6 1 mole C6H8O6 x 1000 mg 1 g DRI 90mg mg C6H8O6 mL Juice number of juice servings to satisfy DRI of ascorbic acid servings of juice to satisfy DRI DRI mg C6H8O6 x mL juice mg C6H8O6 servings of juice to satisfy DRI 90