Lecture 6 Flashcards
Limiting reagent
the reactant that is completely used up in a reaction, and thus determines when the reaction stops
Excess reagent
the reactant that could keep reacting if the other had not been consumed
The ideal gas law
PV = nRT
Acid
A substance that produces H+ ions when dissolved in H2O
Base
A substance that produces OH- ions when dissolved in H2O
Acid based reaction AKA
Neutralization reaction
Kinetic energy
Energy of motion
- mechanical energy
- thermal energy
- electrical energy
Potential energy
Stored energy
- gravitational energy
- electrostatic energy
- chemical potential energy
Electrostatic energy
Energy of charged particles
Chemical potential energy
Energy of attraction or repulsion among electrons and nuclei
Kinetic energy examples
- A bicyclist pedaling up a hill
- Volleyball player spiking a ball
- Walking down the street
- A bowling ball rolling down the alley
- Wind blowing through your hair
Potential energy examples
- Archer with his bow drawn
- Sitting in the top of a tree
- Chemical bonds on sugar
Law of conservation of energy
Energy is neither created nor destroyed, it is only converted between forms
If delta E < 0
Energy is release to the surrounding from system
If delta E > 0
Energy is absorbed from surroundings by system
Internal energy
The sum of PE + KE of all particles that make up the system
Delta E =
w + q
heat + work
Heat
Energy transfer as a result of difference in temperatures
Work
Energy transfer when object moved by force
Chemical reactions and work
- Electrical work
- Work of expansion
Electrical work
Drive electric current through wire
Work of expansion
Volume of system changes
When q is positive
System gains heat
When q is negative
System releases heat
When w is positive
Work is done on system
When q is negative
Work is done by system
Expansion
An increase in the average distance between atoms or molecules in the substance
Contraction
A decrease in the average distance between atoms or molecules in the substance
Expansion work (pressure volume work)
pV=nRT
Explain W = I x d
Work equals the force exerted by a piston of gas times the distance
Explain p = I/A
Pressure equals the force exerted by a piston of gas divided by the surface area on the piston
