Chapter 10: Gases Flashcards
substances that a liquids or solids under ordinary conditions can also exist in the gaseous state, often referred to as _______
vapors
gases differ from liquids and solids by? (4)
- expands to fits its containers
- highly compressible
- homogeneous mixtures
- individual molecules are relatively far apart
conveys the idea of a force, a push that tends to move something
pressure
P = F/A
pressure equation
gravity works w/ gases to creates ________ _______
atmospheric pressure
you can calculate the magnitude of atmospheric pressure F exerted by any object is the product of its mass x acceleration
F = ma
the SI unit for kg-m/s^2 is a ________
Newton
SI unit of pressure is 1. _______ given the name 2. _______
- N/m^2
2. pascal (Pa)
a related unit to the Pascal is the _____ which one equals to 105 Pa
bar
atmospheric pressure @ sea level is ______ Pa or 1 bar
105
who created the barometer?
Evangelista Torricelli
dish experiences the full force of the Earth’s atmosphere and the column of Hg tries to match it as to why it increases —> barometer increased, height of Hg column, amount of atmo pressing down on surface decreases
Torricelli’s argument about pressure
corresponds to the typical pressure @ sea level
standard atmospheric pressure
1.01325 x 10^5 Pa =
standard atmospheric pressure
standard atmospheric pressure defines common non-SI units used to express gas such as 1. _________ and 2. _______
- atmosphere (atm)
2. millimeters of mercury (mm Hg) or torr
operates like a barometer; sometimes used to measure gas pressures near atmospheric pressure; P (gas) = P (atm) + P (height)
manometer
120 in 120/80 in blood pressure
systolic pressure
80 in 120/80
diastolic pressure
reading gauge
systolic pressure
pressure reduced until blood flows freely
diastolic pressure
presence of abnormally high blood pressure greater than 140/90
hypertension
what are the 4 variables for the physical conditions of gas?
- pressure
- volume
- moles of gas (amount of gas)
- temperature
the laws expressed the effect of 1. ____ variable on 2. ______ w/ the remaining two variables held at 3. ________
- one
- volume
- constant
the volume of a fixed quantity of gas maintained @ constant temp is inversely proportional to the pressure
Boyle’s Law
one gets smaller as the other gets larger
inversely proportional
PV = constant
Boyle’s Law
______ was the first to experiment with a variable systematically changed to determine the effect of the other
Boyle
hot air balloons 1. ______ as it’s heated, a balloon will shrink as the 2. _____ is cooled
- expand
2. gas
Pressure-Temperature relationship
Robert Boyle
Temperature-Volume relationship
Jacques Charles
the volume of a fixed amount of gas maintained at constant pressure is directly proportional to it’s absolute temp
Charles’s Law
proposed the absolute temp scale and for what?
William Thomson, for Charles’ Law
experimented on the properties of gas to try and better control lighter-than-air balloons observed the law of combining volumes
Joseph Louis Gay-Lussac
@ a given temp and pressure, the volumes of gases that rect w/ one another are in ratio of small whole numbers (like empirical formulas?)
law of combing gases
based on Gay-Lussac’s observations, = volumes of gases @ the same temp + pressure contain the same # of molecules
Avogadro’s Hypothesis
follow fr. hypothesis: the volume of a gas maintained at constant temperature and pressure is directly proportional to the # of moles of the gas
Avogadro’s Law
PV = nRT
ideal-gas equation
a hypothetical gas whose pressure volume, and temperature behavior are described completely by the ideal-gas equation
ideal gas
what is absolute temperature?
the Kelvin scale
the term “R” in the ideal-gas equation
gas constant
the gas constant is _________ on units of pressure, volume, moles of gas, and temperature
dependent
temp in the ideal-gas equation must _______ be expressed as absolute temp
ALWAYS
in the ideal-gas equation:
- pressure = ______
- volume = _______
- quantity of gas in ______
- temp in ______
- atm
- L
- moles
- Kelvin
Product PV has units of energy, so units of __ can contain joules or calories
R
in problems of ideal-gas equations, units of P, V, n, and T must ______ w/ the gas constant
agree
0.08206 L-atm/mol-K
value of R for units of atm in pressure
8.314 J/mol-K
value of R for units of Pa in pressure
conditions 0 degrees C and 1 atm are referred to _______ _______ ________
standard temperature pressure (STP)
22.41L can be seen as the ______ mass of an ideal-gas @ STP
molar
measure V might ____ from PV = nRT
differ
nRT are all constants so must be the product of ___
PV
P and V can change values independently but when together, their product must be a ________
constant
P1V1 / T1 = P2V2 / T2
combined gas law
nM/V = PM/RT
the relationship b/w gas densities and molar mass
M in the relationship is. . .
molar mass; # of grams in one mole of substance
d = PM/RT
density of gas
density of gas depends on (3)
- pressure
- molar mass
- temperature
though gas forms homogeneous mixtures, a 1. ______ dense gas will lie above a 2. _____ dense gas in the absence of 3. _______
- less
- more
- mixing
M = dRT/P
molar mass of a gas
