Question | Answer |
energy | power which may be translated into motion, overcoming resistance, or effecting physical change; the ability to do work. Symbol E |
work | energy used to move an object against an opposing force |
kinetic energy | energy of motion 1/2 mass x volume squared |
potential energy | Potential energy is that energy which an object has because of its position |
law of conservation of energy | first law of thermodynamics-energy cannot be created nor destroyed, just transferred |
system and surroundings | when energy flows into a system from the surroundings, the system gains energy(from/into/loses) |
heat | transfer of thermal energy between system and surroundings |
heat capacity | amount of heat required to raise one mole of substance by one degree Celsius |
specific heat | amount of heat per unit mass required to raise one mole of substance by one degree Celsius |
first law of thermodynamics | Law of conservation of energy-energy cannot be created nor destroyed, just transferred |
bond energy | amount of energy required to break a covalent bond |
exothermic | loss of energy delta E is - |
endothermic | gain in energy delta E is + |
calorimeter | container designed to create an isolated system, so that heat measurements can be carefully made(either constant-volume or constant-pressure) |
enthalpy | delta H-heat for a process under constant pressure conditions |
delta H = | delta E + P(delta V) |
P x V = | n x R x T |
heat of solution | energy released or required to dissolve a specific quantity of a a given substance in water |
heat of dilution | energy released or required to dilute an existing solution |
Molar Heat of Fusion | energy required to melt one mole of a given substance |
Molar Heat of Vaporization | energy required to evaporate one mole of a given substance |
standard heat of formation | delta Hf- delta Hrxn to create 1 mole of product from its elements in their standard states |
Hess' Law of heat summation | the overall heat gain/loss in a chemical process equals the sums of the enthalpy changes in each step of the process(delta Htot=delta H1 + delta H2 + ...) |
molar energy change | (delta Emolar)change in energy for a process that involves one mole of a given material |
work = | -external pressure x change in volume |
change in energy of the system equal | system heat plus system work |
change in energy of the universe | change in energy of the system plus the change in energy of the surroundings which equals zero |
measurement for energy | joule(J)=1 N m=1 kg m squared/seconds squared |
1 L atm | 101.325 joules |
1 calorie | 4.184 Joules |
1 Cal | 1 kcal |
1st Step in calculating energy change using a calorimeter | take measurements of the mass of the material and before temperature |
2nd Step in calculating energy change using a calorimeter | mix chemical reagents being studies directly in the calorimeter and measure after temperature |
3rd Step in calculating energy change using a calorimeter | calculate where change in energy(delta q)=mass of the solution(m) x change in temperature(delta t) x specific heat of the solution(water=1.00 cal/gC or 4.185 J/gC) |
reaction energy(delta Hrxn)= | sum of bond energies broken - sum of bond energies formed |