Chem 103 Final Exam Latest Updated 2025

Ecific heat S=q/m△t, q=ms△t Heat capacity C=q/△t, q=c△t Coffe cup calorimetry Sm= (-mw)(sw)(△tw)/(mm)(△tm) qwater=-qmetal Coffee cup calorimetry part 2 1. Qsolid=(-maq )(saq) (△taq) 2. Qsolid=-qaq In coffee calorimetry, in increase in temperature Means the reaction was "exothermic" and is negative. In coffee calorimetry, if the temperature drops during the reaction, Then the reaction must be endothermic and is positive. System does work on surroundings (releases energy) -w Surroundings does work on system (absorbs energy) +w Exothermic Releases heat, -q Endothermic Absorbs heat, +q Work Transfer of energy from one form to another Heat Total kinetic energy that gets transferred from one substance/object to another Potential energy Stored energy Kinetic energy Chemistry Chemistry Energy of motion Law of conservation of energy Energy cannot be created or destroyed. △esystem=-△esurroundings 1kcal 1000 cal Relationship between energy, heat, and work △e=q+w Energy as a product Exothermic Energy as a reactant Endothermic System The "thing" being studied Surroundings The rest of the universe What atoms can form expanded octets? S, p, si, cl How do you find the best lewis structure? How do you know which lewis structures have resonance? -the best lewis structure would be the lewis structure with the fewest charges possible -if they have nonzero formal charges on one or two atoms in a lewis structure. If it is neutral, it does not have a resonance Resonance structures A set of structures that show how electrons are distributed. Used when a single lewis structure is insufficient How do you find the average charge of an atom on a lewis structure? #of atoms the (-) or (+) is on/total atoms of the lewis structure A double bond when figuring out electronic geometry...... Counts as one Electronic geometry Chemistry Chemistry Arrangement of electrons around the central atom Molecular geometry Shape caused by the arrangement of atoms Linear eg & mg Two electron groups, 180° Trigonal planar eg Three electron groups, 120° Tetrahedral eg Four electron groups, 109.5° Eg is trigonal planar. What is the mg? 3 bonding groups, 0 lone pairs Trigonal planar Eg is trigonal planar. What is the mg? 2 bonding groups, 1 lone pair Bent Eg is tetrahedral. What is the mg? 4 bonding groups, 0 lone pairs Tetrahedral Eg is tetrahedral. What is the mg? 3 bonding groups, 1 lone pair Trigonal pyramidal Eg is tetrahedral. What is the mg? 2 bonding groups, 2 lone pairs Bent Summary of eg and mg Picture--- Chemistry Chemistry Nonpolar covalent 0.5 Polar covalent 0.5-2.0 Ionic 2.0 If it is polar It has a net dipole If it is nonpolar No net dipole It is nonpolar if... All point away from the central atom (all dipoles cancel) **if there are lone pairs on the central atom it doesn't let it cancel so it is polar** Net dipole has to..... Point to the most electronegative atom Solid Particles are close together and held in a fixed position. Definite shape and volume Liquid Particles are close together but move freely past each other. Definite volume; adopts the shape of the container Gas Particles are far apart and have very little interaction. Adopts shape and volume of container. No definite shape or volume. Intramolecular forces Bonds within a molecule. Covalent bonds are the intra forces present in a molecular solid (ionic and covalent) Intermolecular forces Are the weaker forces between different molecules (dipole-dipole, hydrogen bonds, dispersion forces) Chemistry Chemistry Ionic substances -strongest intramolecular force -almost always solid at room temp -high mp/bp -nonmetals and metals (+, -) Molecular solids -solids that are composed of molecules held togethe