Unit 5, Gas Laws Flashcards
(16 cards)
Pressure
Force per unit area
Absolute pressure
Absolute pressure is the measurement of pressure relative to a perfect vacuum, or absolute zero pressure.
Atmospheric pressure
the force exerted by the weight of the Earth’s atmosphere on a surface. It’s the pressure caused by the constant bombardment of air molecules on a surface, and it varies with altitude and temperature
Boyle’s Law
P1V1=P2V2
- Decreasing volume increases collisions and increases pressure
- Pressure and volume are inversly related, in constant temp and moles of gas
Charles’s Law
- Volume and temp (in kelvin) are directly related (constant p & n)
- Celsius to kelvins: Tk=Tc+273.15
- V1/T1=V2/T2
Combined Gas Law
(P1V1)/T1 = (P2V2)/T2
Gay-Lussac’s Law
P1/T1 = P2/T2
Ideal Gas
An ideal gas is a gas with a very simple relationship between pressure, volume, and temperature. The product of pressure and the volume of an ideal gas is directly proportional to the number of moles of the gas and the absolute temperature. In an ideal gas, pressure is directly proportional to temperature.
PV = nRT
Real Gas
A real gas is defined as a gas that at all standard pressure and temperature conditions does not obey gas laws. It deviates from its ideal behaviour as the gas becomes huge and voluminous. True gases have velocity, mass, and volume.
Dalton’s Law of Partial Pressures
-used in dealing with a mix of gases
Ptotal=P1+P2+P3+…
Relative Humidity
Relative humidity is the amount of water vapor present in the air compared to the maximum amount it could hold at a given temperature. It’s expressed as a percentage, indicating how close the air is to being saturated with moisture. For example, 50% relative humidity means the air is holding half of its maximum possible moisture
Relative Pressure
Relative pressure is a measure of pressure that compares the pressure of a gas to a reference pressure, typically atmospheric pressure.
Temperature
Temperature is the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius.
Kelvin temperature scale
- Tk= Tc + 273.15
- unit: k
- 0k is absolute zero, temp obtained by extrapolation to zero volume
- absolute zero on kelvin scale is -273.15 degrees celsius
Melting point
The melting point of a substance is the specific temperature at which it transitions from a solid to a liquid state
Boiling point
The boiling point of a substance is the temperature at which its vapor pressure equals the surrounding atmospheric pressure, causing it to transition from a liquid to a gaseous state.
