Unit 1B: Solids, Liquids, & Gases Flashcards
Kinetic theory
All matter consists of tiny particles that are in constant motion
Gas pressure
The result of simultaneous collisions of billions of rapidly moving particles in a gas with an object
Atmospheric pressure
Results from the collisions of atoms and molecules in air with objects
Pascal (Pa)
The SI unit of pressure, 1 atm = 100,000 Pa = 1 kPa
Standard atmosphere (atm)
The pressure required to support 760 mm Hg in a mercury barometer at 25*C
Combined gas law
If the amount of gas is constant, P1V1/T1 = P2V2/T2
Ideal gas law constant
R = 8.31 (LkPa)/(Kmol)
Ideal gas law
PV = nRT
Partial pressure
The contribution each gas in a mixture makes to the total pressure exerted by the gas
Dalton’s law of partial pressure
At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of the component gases:
P(total) = P1+P2+P3+…
Surface tension
The inward force that tends to minimize the surface area of a liquid
Surfactant
Any substance that interferes with the hydrogen bonding between water molecules and reduces surface tension
Aqueous solution
Water that contains dissolved substances
Solvent
The dissolving medium in a solution
Solute
The dissolved particles in a solution
Electrolyte
A compound that conducts an electric current when it is in an aqueous solution or its molten state
Hydrate
A compound that contains water of hydration (the water contained in a crystal)
Describe the assumptions of kinetic theory as it applies to gases.
- the particles in a gas are considered to be small, hard spheres with an insignificant volume,
- There are no attractive forces between molecules.
Convert atm’s to kPa’s.
1 atm = 101.3 kPa
Understand the Kelvin scale and how it relates to kinetic energy.
The Kelvin scale is directly proportionate to the average kinetic energy of the molecules.
K = *C+273
Explain the role of external pressure in determining the boiling point of a liquid (pages 392-395).
With less external pressure, the molecules within the liquid can break away easier. When pressure decreases, the boiling point also decreases.
How do crystal systems differ?
In the patterns in which their molecules are arranged, which effects the shape of the crystal
How does pressure affect the movement of gas particles?
The higher the pressure, the higher the temperature if all other factors remain constant
Boyle’s law
P1V1 = P2V2
How are real gases different from ideal gases?
- Ideal gases follow all the gas laws under all conditions
- The particles in an ideal gas would have no volume and there would be no attraction between the particles
Be able to predict which molecules would be soluble in water.
Ionic compounds and polar covalent molecules
Suspension
A mixture from which the particles settle out upon standing; largest particles
What causes Brownian motion?
The chaotic movement of colloidal particles
List three factors that can affect gas pressure.
- volume (V), measured in liters
- temperature (T), measured in kelvins
- number of moles (n)
Explain why ice is less dense than liquid water.
The positively charged hydrogen atoms in the water molecules keep the negatively charged oxygen atoms of other water molecules at a set difference away. The water molecules in ice are arranged in a regular framework like a honey comb. This means the water molecules in ice are farther apart than in liquid water.
Charles’s law
V1/T1 = V2/T2
*Temp is in Kelvins
Gay-Lussac’s law
P1/T1 = P2/T2
*Temp is in Kelvins
Colloids
A mixture containing particles of medium size (1 nm- 1000 nm)
Solutions
A homogeneous mixture that has tiny particles that can’t be filtered out
