Gases Flashcards
Pressure
the normal force applied to a unit area of a surface
Temperature
measures average kinetic energy
Volume
the amount of space something takes up
Charles Law
Temp vs Volume
- As temp increases, volume increases
- Direct relationship
Gay Lussac’s Law
Temp vs Pressure
- As temp increases, pressure increases
- Direct relationship
Boyle’s Law
Pressure vs Volume
- As pressure increases, volume decreases
- Indirect relationship
Gases of the same volume have:
the same number of molecules
Combined Gas Law Equation
P1 V1 P2 V2
——– = ———-
T1 T2
What are things that you need to remember for using combined gas law?
- Cross out all values that are held constant
- Always put temp in KELVIN
- STP is on Table A
400mL of gas, at constant Pressure, is at 50°C. What will be the new volume at 300°C?
2400 mL
Kinetic Molecular Theory
Used to explain the behavior of gases
Shows relationships between pressure, volume, and temperature on gases
Part 1 of KMT
Gas particles are in constant, random, straight-line motion and only change direction when they collide
Part 2 of KMT
When particles collide with one, another energy is transferred (not lost) from one particle to another
Part 3 of KMT
Particles are so small that their volumes are considered to be zero (negligible)
Part 4 of KMT
Gas particles have no attractive forces for one another!
Ideal Gases
- Particles have no Volume
- No attractions or repulsions
- Collide without loss of energy
Real Gases
- Have volume
- Have attraction b/w particles
- Some energy can be transferred to surroundings
How can real gases behave most like ideal gases?
- High Temperature
- Low Pressure
Which elements are most like ideal gases?
Hydrogen and Helium are most like ideal gases because they are SMALL!!!
What is vapor pressure?
The pressure the liquid exerts on the side of the container it is in. When the vapor pressure reaches atmospheric pressure, the liquid boils
The lowest vapor pressure has
- The highest BP
- Strongest intermolecular forces
High vapor pressure has
- Lowest BP
- Weakest intermolecular forces
Avogadro’s Hypothesis
equal volumes of gases have the same number of molecules
Percent Error Equation
Real - Theoretical
————————– x 100
Theoretical