CHEM 103: FINAL EXAM QUESTIONS
AND COMPLETE DETAILED ANSWERS
Specific heat - Answer: s=q/m△T, q=ms△T
heat capacity - Answer: C=q/△T, q=C△T
Coffe cup calorimetry - Answer: Sm= (-Mw)(Sw)(△Tw)/(Mm)(△Tm)
Qwater=-Qmetal
Coffee Cup calorimetry part 2 - Answer: 1. Qsolid=(-Maq )(Saq) (△Taq)
2. Qsolid=-Qaq
In Coffee calorimetry, in increase in temperature - Answer: means the reaction was "exothermic"
and is negative.
In coffee calorimetry, if the temperature drops during the reaction, - Answer: then the reaction
must be endothermic and is positive.
System does work on surroundings (releases energy) - Answer: -w
Surroundings does work on system (absorbs energy) - Answer: +w
exothermic - Answer: Releases heat, -q
endothermic - Answer: Absorbs heat, +q
work - Answer: transfer of energy from one form to another
heat - Answer: total kinetic energy that gets transferred from one substance/object to another
, potential energy - Answer: stored energy
kinetic energy - Answer: energy of motion
Law of Conservation of Energy - Answer: Energy cannot be created or destroyed.
△Esystem=-△Esurroundings
1kcal - Answer: 1000 cal
Relationship between energy, heat, and work - Answer: △E=q+w
energy as a product - Answer: exothermic
energy as a reactant - Answer: endothermic
system - Answer: the "thing" being studied
surroundings - Answer: the rest of the universe
What atoms can form expanded octets? - Answer: S, P, Si, Cl
How do you find the best lewis structure? How do you know which lewis structures have resonance?
- Answer: -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 - Answer: 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? - Answer: #of atoms the (-) or
(+) is on/total atoms of the lewis structure
AND COMPLETE DETAILED ANSWERS
Specific heat - Answer: s=q/m△T, q=ms△T
heat capacity - Answer: C=q/△T, q=C△T
Coffe cup calorimetry - Answer: Sm= (-Mw)(Sw)(△Tw)/(Mm)(△Tm)
Qwater=-Qmetal
Coffee Cup calorimetry part 2 - Answer: 1. Qsolid=(-Maq )(Saq) (△Taq)
2. Qsolid=-Qaq
In Coffee calorimetry, in increase in temperature - Answer: means the reaction was "exothermic"
and is negative.
In coffee calorimetry, if the temperature drops during the reaction, - Answer: then the reaction
must be endothermic and is positive.
System does work on surroundings (releases energy) - Answer: -w
Surroundings does work on system (absorbs energy) - Answer: +w
exothermic - Answer: Releases heat, -q
endothermic - Answer: Absorbs heat, +q
work - Answer: transfer of energy from one form to another
heat - Answer: total kinetic energy that gets transferred from one substance/object to another
, potential energy - Answer: stored energy
kinetic energy - Answer: energy of motion
Law of Conservation of Energy - Answer: Energy cannot be created or destroyed.
△Esystem=-△Esurroundings
1kcal - Answer: 1000 cal
Relationship between energy, heat, and work - Answer: △E=q+w
energy as a product - Answer: exothermic
energy as a reactant - Answer: endothermic
system - Answer: the "thing" being studied
surroundings - Answer: the rest of the universe
What atoms can form expanded octets? - Answer: S, P, Si, Cl
How do you find the best lewis structure? How do you know which lewis structures have resonance?
- Answer: -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 - Answer: 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? - Answer: #of atoms the (-) or
(+) is on/total atoms of the lewis structure
