Chapters 4 and 5 Flashcards
for quiz/test
What are the first 3 gas laws? What are the equations?
Boyle’s Law, Charles’ Law, and Avogadro’s Law. P1V1 = P2V2; v1/t1=v2/t2; v1/n1=v2/n2
What is a barometer? Who invented it? How?
A device for measuring pressure in Torr. Evangelista Torricelli. He filled a glass tube with Hg and inverted it into a dish. At sea level, the height was 760mm.
What is a manometer?
Measures pressure of gas in a container.
How do you measure the pressure of a gas using a barometer?
pressure in air - pressure in barometer with gas
How many mmHg (torr) are in 1 atmosphere?
760
atm to Psi?
14.69
What is STP?
0C (273.15K) and 1 atm
What is the molar volume of an ideal gas?
22.41L
What is the ideal gas law? Units?
PV = nRT…. P: pressure (atm) ; V: volume (L) ; n: moles; T: temp (K); R: 0.08206 (L * atm)/(mol * K)
What is an ideal gas?
a gas that obeys boyle;s law
Ideal Gas Law problem
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Dalton’s Law of partial pressure
Ptotal = P1+P2+P3+…
What is a mole fraction?
the ratio of the number of moles of a given component to the total # of moles in the mixture
What is vapor pressure?
the pressure of a vapor over a liquid at equilibrium
Vapor pressure/partial pressure practice problem
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Kinetic Molecular Theory’s postulates?
4 postulates:
1. particles are so small and far apart that the volume of molecules is negligible
2. particles are in constant motion, pressure is caused by these particles hitting the walls of the container
3. particles are assumed to have 0 intermolecular forces
4. the average kinetic energy of a collection gas particles is assumed to be directly proportionate to kelvin temp
REAL GASES DO NOT FOLLOW THESE ASSUMTIONS
Equation for average kinetic energy of molecules
(KE)avg = 3/2(RT), R = 8.3145 J/(molk)
units of a J?
kg*m^2/s^2
Root mean square velocity?
sqrt(3RT/m) where m is the molar mass in Kgs!!!
Root Mean Square and Average KE problems
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Gas stoichiometry practice problems in notes
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Finding empirical and molecular formulas with gases problems
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What 2 conditions does the ideal gas law describe the behavior of a gas more accurately in?
high pressure and low temp
Real Gas Law
Pobs = [(nRT)/(V-nb)] - a(n/v)^2 where b is the size of a molecule, and a is a measure of interparticle force of attraction
Real Gas Law Problem
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What does like dissolves like mean?
polar substances dissolve polar substances and nonpolar substances dissolve nonpolar substances