Sci 2 Flashcards
What is a mixture that looks like a single substance called?
solution
During what two centuries was the behavior of gases heavily explored?
seventeenth and eighteenth
What is Boyle’s law?
The volume of a gas is inversely proportional to its pressure when the number of gas molecules and the temperature remain constant
Charles’s law
at constant pressure, the volume of a fixed amount of gas is proportional to its absolute temperature
At what temperature (celsius) does zero volume occur?
-273
At what temperature is absolute 0?
0 k (-273 c)
What equation combines Boyle’s and Charles’ laws?
PV/T=CD
What interest primarily motivated Jacques Charles?
hot air balloons
What Anglo-Irish chemist’s work did Jacques Charles study?
Robert Boyle
What did Charles use to fuel balloon flight?
Hydrogen
What two engineers did Charles work with for his first balloon?
Anne-Jean and Nicolas-Louis Robert
When was the first hydrogen-powered balloon launched?
August 27 1783
How long did the first hydrogen-powered balloon flight last?
forty five minutes
When did the first manned balloon flight take place?
December 1, 1783
Who was on board the first manned balloon flight?
Charles and Nicolas-Louis Robert
Why did Charles stop balloon flights?
ear pain
What was the hydrogen balloon known as?
Charliere
What is Jacques Charles best known for?
work with gases
Who credited Charles with discovering Charles’s Law?
Joseph-Louis Gay Lussac
How could the relationship between moles and pressure be described?
Directly proportional
What are the four assumptions of the kinetic-molecular theory of gases?
The actual volume of gas volumes is negligible, molecules are all moving, but at different speeds, no attraction or repulsion exists between one molecule and another, gas pressure results from collisions of molecules with the walls of the container
Using the assumptions of the KMT, what equation gives force?
F=mu^2/l, where m is mass, u is speed towards wall, and l is length (meters)
What does Force/area equal?
pressure
What does the molecular theory of matter suggest as the determinant of matter states?
number of molecules
Avogadro’s Law
Equal volumes of an ideal gas contain equal numbers of particles
Avogadro’s Law conclusion
volume of a gas is directly proportional to the number of moles of the gas
What is the mole based on?
number of carbon atoms in 12 grams of carbon-12
What is Avogadro’s number?
6.022x10^23
Who actually determined Avogadro’s number?
Jean Baptiste Perrin
In what year was Avogadro’s number estimated by Perrin?
1909
What did Avogadro propose that the volume of a gas is directly proportional to?
number of moles of a gas
What was the original definition of a mole?
number of molecules in a volume of 22.4 liters at 1 atmosphere and 273 K
What would be the mass of one of Avogadro’s number of helium atoms?
4 grams
What is helium’s molar mass?
4 g/mol
What is the molar mass of methane?
16 g/mol
What is the energy of motion directly related to?
temperature
What does the energy of a molecule equal?
3/2 kT
what is k in the formula for the energy of a molecule?
Boltzmann constant
What is the molar mass of NaCl?
58.5 g/mol
What is the ideal gas equation?
PV = (1/3M)x(3RT/M)=RT
What German Swedish chemist is partially credited with discovering Oxygen?
Carl Wilhelm Scheele
When was O2 first produced by a scientist?
1772
Who was the first scientist to produce O2?
Scheele
What did Scheele call O2?
fire-air
Who heated mercuric oxide and observed its interaction with flames?
Joseph Priestly
What did Priestly believe materials emitted as they were heated?
phlogiston
Who is most often credited with the discovery of oxygen?
Joseph Priestly
How many gases did Priestly discover?
eight
Who wrote a letter to Antoine Lavoisier describing his experiments with oxygen?
Shceele
Who firstcame to an understanding of how combustion worked?
Lavoisier
What are the three key assumptions of the kinetic-molecular theory?
gas molecules have no volume, there are no intermolecular forces between molecules, only kinetic energy is transferred
Who developed an equation to monitor the behavior of non-ideal gases?
Johannes van der Waals
what does van der Waals’ a-value account for?
attraction that gas molecules have for each other during collisions
what does van der Waals’ b-value account for?
volume of the gas molecules
What do good choices for refrigerator liquids have?
high van der Waals constants
What was used for refrigeration for many years?
CFCs
What are CFCs no longer used?
ozone layer depletion
What two gases are often now used in fridges?
Ammonia and carbon dioxide
Does octane have notably weak or strong forces between molecules?
weak
What are the four types of solids
ionic lattice, covalent network, molecular, metallic
When a chemical compound or element can have several different solid forms, what are the different forms called?
allotropes
Is graphite an insulator or a conductor?
conductor
Is diamond an insulator or a conductor?
insulator
What is the most stable form of carbon?
graphite
What is natural carbon formed from?
graphite
What type of molecule has the most closely packed structure?
pure metals
What makes pure metals pure?
having one element
What type of structure do metals have?
crystalline
How are the three forms of metals determined?
the number of similar particles at the nearest distance an ato mhas
What are the three simplest structures seen in a pure metal?
body-centered cubic, face-centered cubic, and close-packed hexagonal
Name one example of body-centered cubic metal structure
iron
Name one example of face-centered cubic
silver
Name one example of close-packed hexagonal
zinc
How many nearest neighbors does body-centered cubic structure have?
8
How many nearest neighbors do face-centered and close-packed hexagonal have?
12
What makes some metals softer?
closer packing of molecules
Why are metals good conductors?
closeness of their structure
What does “ductile” describe?
how easily metal can be pulled into a wire
What is the process through which molecules move from one phase to another called?
dynamic transfer
Under what condition is dynamic equilibrium achieved?
rates at which particles leave and enter a phase are the same
At what point on a phase diagram can solids, liquids, and gases exist in equilibrium?
triple point
At what point is the distinction between gas and liquid no longer apparent?
critical point
At what temperature and pressure is the critical point for water?
374, 218
At what pressure can liquid CO2 be observed?
5.11 atm
At what atmosphere and temperature is the triple point for CO2?
-56.4 C
What is CO2’s supercritical point?
73 atm and 31.1 C
Who is credited with the discovery of carbon dioxide?
Joseph Black
What did Joseph Black call carbon dioxide?
fixed air
What was Black heating when he discovered carbon dioxide?
limestone
What was lime water believed to be effective in treating?
kidney stones
What two things did Black note that carbon dioxide could do?
extinguish flames and kill animals
What was Black’s 1755 paper titled?
Experiment upon Magnesia Aba, Quicklime, and Some Other Alcaline Substances
What other three gases were isolated for the first time soon after carbon dioxide?
hydrogen, nitrogen, and oxygen
What is the substance present in the largest amount in a solution called?
solvent
What type of molecule interacts strongly with electrically charged solutes?
polar
How are solvents typically distinguished (2)?
polar and nonpolar
What is the most important polar solvent?
water
All common compounds of Group __ and ___ ions are soluble
Group I and ammonium
All ___,___ and ___ are soluble (ates)
nitrates, acetates, and chlorates
In what solvent are lead halides soluble?
hot water
What sulfates are not soluble? (6 elements)
those of barium, strontium, calcium, lead, silver, mercury
What is a solution containing the maximum amount of a solute called?
saturated solution
solubility for most substances increases with ____ temperature
increasing
How can water be tested for chloride ions?
silver ions can be added to form a precipitate
How are carbonate ions formed in water in a cave?
carbon dioxide dissolves in the water
What type of bond does glucose engage in with water?
hydrogen
are intermolecular forces in nonpolar solvents typically strong or weak?
weak
What is one problem with the use of nonpolar solvents?
disposal
What is the only way to remove nonpolar solvents from the environment?
burn them
What are the two ends of soap and detergent molecules?
polar and nonpolar
What units is molarity expressed in?
moles per liter
