Principles of Chemistry Flashcards
What are the properties of solids?
- fixed shape
- fixed volume
- cannot be compressed
What are the properties of liquids?
- no fixed shape, take shape of their container
- fixed volume
- can flow
- cannot be compressed
What are the properties of gases?
- no fixed shape, take shape of their container
- no fixed volume, take up volume of their container
- can flow
- can be compressed
Describe the structure of solids.
- regular arrangement
- particles tightly packed (touching each other)
- vibrate about their fixed position
Describe the structure of liquids.
- no regular arrangement
- tightly packed particles (less than solid)
- particles further apart
- move randomly at different speeds, not far as they frequently collide with other particles
Describe the structure of gases.
- no regular arrangement
- particles move randomly at different speeds, much faster than liquids
- particles separated
solid to liquid
melting
solid to gas
sublimation
liquid to solid
freezing
liquid to gas
evaporating/boiling
gas to solid
deposition
gas to liquid
condensing
Explain changes of state in terms of the kinetic theory.
temperature of a substance increases, the average KE of particles rises, gain enough energy to overcome forces of attraction
vice-versa for temperature drop
Describe the effects of temperature on the volume of a gas.
temperature of gas increases, particles move faster and further (still randomly), increasing distance between particles, so the volume of the gas increases
Describe the effects of pressure on the volume of a gas.
- increase the pressure of a gas, volume decreases
- same number of particles, less volume.
- same number of particles will exert more collisions on the sides of the container, increasing pressure
Define diffusion.
movement of particles from an area of high concentration to an area of low concentration, until the concentrations are even throughout
State factors which affect diffusion rate.
- temperature
- concentration gradient
- molecular mass
What is a concentration gradient?
The difference in concentration of a fluid between two connected areas
What is the effect of molecular mass on rate of diffusion?
the greater the molecular mass, the slower the molecules move, decreasing RoD
Explain the dependence of rate of diffusion on molecular mass.
larger molecules carry more mass, need more KE than smaller molecules to move the same distance
What is an element?
chemical substance that cannot be broken down into simpler substances and is composed of only one type of atom
What is a compound?
substance made of two or more elements chemically bonded together