AP Chemistry Unit 6 - Thermodynamics | Kentucky State University

University:
Kentucky State University
Course:
CHE 101 | General Chemistry I
Academic year:

2022
Views:

189

Pages:

1
Author:

Braiden Lam

Unit 6 - Thermodynamics Potential Energy - energy associated with position Kinetic Energy - energy associated with motion, KE=1/2mv² Thermal Energy - energy associated with temperature with relation to mass System - reactants and products Surroundings - everything else including thermometer, container, etc. Exothermic - energy is released to surroundings, ΔH<0, temperature of surroundings(including thermometer) increases, phase change in direction of gas to solid Endothermic - energy is absorbed from surroundings, ΔH>0, temperature of surroundings(including thermometer) decreases, phase change in direction of solid to gas First Law of Thermodynamics - energy cannot be created or destroyed, total energy is constant Ways to find ΔH: 1. q=mcΔT, ΔH=q/n, n=moles of limiting reactant 2. Use a table to calculate bond enthalpies. Draw the lewis dot diagrams for each molecule and count the number of each type of bond. Add each bond enthalpy together for reactants and products. Subtract sum of bond enthalpies in products form the sum of bond enthalpies in reactants. 3. Use a table of standard enthalpy of formation Δ𝐻𝑓 . Subtract the sum of enthalpies of each reactant molecule from the sum of enthalpies of each product molecule. 4. Use Hess’s Law - flip and multiply given equations to make your desire equation a. If you multiply the coefficients by x, you multiply the ΔH by x. b. If you flip the reaction, you reverse the sign of ΔH. Molar Heat Capacity - molar mass multiple by specific heat ΔE=q+w=heat+work w=-PΔV