# Chemistry Week 3

 Stoichiometry Requires a balanced equationUse coefficients to balance Limiting Reagent Is it the cheese or the bread that limits the sandwiches?Has to do with population size (moles) NOT grams or weight Grams to Volume Molar M= moles Liter Concentration What is printed on the bottledNumber of moles present in a certain volume of solutionConcentration x Volume= Moles Dilution Equation (Cstock)(Vstock)= (Cwant)(Volumewant) Equations for Concentration CxV=MolesMxV=MolesMolesxL= Moles Potential Energy PEPE=MghConvert to joules Kinetic Energy KEKE=1/2MV2Convert to Joules M mass g acceleration due to gravity h height of object V velocity Specific Heat Cmeasure of how strongly molecules or atoms are boundC=Joules (Kg)CoLarge amount of heat to make temperatures rise 1o = strong bondReverse is true c specific heat Q Joules /\T= Tfinal-Tstarting Specific Heat of Water Cwater=4186 J/(Kg)Co Alitropes Atoms in different configurations/ chemical structure Isimers Molecules in different configurations Balancing (Stoichiometric) Coefficient Numerical multiplier of all the atoms in th formula that follows it Molar Mass M=g/mol Molar Mass Compounds Sum of mass of atoms in formula Chemical Equation Statement in formulas that express the identities and quantities of the substances involved in a chemical or physical change. Stoichiometrically Equivalent A definite amount of one substance is formed from, produces or reacts with a definite amount of the other. Actual Yield Amount of product that are actually obtained. Percent Yield Actual Yield X 100%Theortical Yield Electrolyte Substance that conducts a current when dissolved in water AcidBase Reaction When an acid reacts with a baseNeutralization reaction Acid Produces H+ ions when disolved in water. Base Produces OH- ions when disolved in water Titration One solution of known concentration is used to determine the concentration of another solution through monitored reaction. Equivalance Point All moles of the H+ ions (acids) react with same number of OH- (base) ions. End Point( When titration occures and when a tiny excess of OH- (base) changes to its color Enthalpy (H) Thermodynamic variable Exothermic Heat-out. Releases HeatDecreased(-) Endothermic Heat-inAbsorbs HeatIncrease(+) Specific Heat Capacity Quantity of heat required to change its tempurature by 1Co Calorimeter used to measure heat released/ abosrbed by a physical or chemical process. Hess's Law of Heat Summation The enthalpy change of an overall process is the sum of the enthalpy changes./\H + /\H1= /\H2A+B=C Reagent substance or compound that is added to a system in order to bring about a chemical reaction or is added to see if a reaction occurs Limited Reagent What mass of ___ can be produced from _____1) Find mole ration of what you NEED (eg 1 mole ----> 2mole2) Find moles of substances3) Divide both by the smallest to determine # of moles4) Compare with need- that which is less than need is limited reagent Theoretical Yield 1) Balance the reaction and determine the stoichiometry or ratios of reactants to products.2) Find the number of moles of each starting material used.3) Determine which reagent is limiting.4) Calculate the moles of product expected if the yield were 100% based on the limiting reagent. (moles x grams)5) Calculate the grams of product corresponding to the number of moles expected. Dilution Spreading out of solute Volume of orginal solution + Volume of added solvent = Volume of diluted solution Indicators Sustances which undergo a detectable chage at the completeion of a seperate chemical reaction. Usually Acid-Base indicators undergo a color change at the completion of Acid-Base Titration Litums Dye extracted from the inner bark of a south american tree. Six Forms of Energy Chem Nursing Lecture ChemicalHeatElectricalMechanicalNuclearLight All forms of enrgy are... Interconvertible Conservative System When all of the PE can be converted to KE and vice versaInterconvertiblity Deforming and object Overcoming Friction System in which energy is lostNonconservative Thermodynamics The study of heat flow or how energy is converted to useful heat and work Calori amount of heat when added to 1gram of water cause the temperature to rise 1oC Specific Heat amount of heat added to specifically 1kilogram of a substance to raise its temperature 1oCSpecifies certain conditionsReversible (rising dropping) Dulong's Petit's Law Specific Heat of metals, when multiplied by their molar mass is a constant.Implies that metals share the same type of bonding. <--------> Reversible Reaction State Functions Path Independent STooP Standard Temperature and Pressure0oC (standard temperature)1atm (standard pressure Standard State The physical state (gas, liquid or solid) in which an element or compount is found at:25oC (room temperature)1atm (standard pressure) /\H Change in Enthalpy /\Horxn= Sum of all /\Hof (products) - Sum of all /\Hof (Reactants) Heat or Enthalpy of any Reaction Combustion Calorimeter Measures the heat evolved in a chemical reaction Authorchiroclown ID26010 Card SetChemistry Week 3 DescriptionTest 3 Updated2010-07-08T05:17:27Z Show Answers