Test 4 – Chemistry Test Answers – Flashcards
Unlock all answers in this set
Unlock answersquestion
What uniformly fill any container, are easily compressed, and mix completely with like substances? |
answer
gases |
question
Earth's atmosphere is about what percent of nitrogen? |
answer
78% |
question
Earth's atmosphere is about what percentage of oxygen gas? |
answer
21% |
question
The universes about what percent of hydrogen gas? |
answer
75% |
question
What results from the weight of the air (mass of air is being pulled toward the center of earth by gravity)? |
answer
atmospheric pressure |
question
Who invented the barometer in 1643? |
answer
Evangelista Torricelli |
question
device used to measure atmospheric pressure |
answer
barometer |
question
What corresponds to bad weather? |
answer
low atmospheric pressure |
question
What is atmospheric pressure at sea level? |
answer
760mmHg |
question
What is the atmospheric pressure in higher elevations (such as Breckenridge, Colorado)? |
answer
520mmHg (thin air) |
question
1atm= |
answer
760mmHg |
question
760mmHg= |
answer
760torr |
question
760torr= |
answer
1atm |
question
force/area |
answer
pressure |
question
what is measured in Newtons? |
answer
pressure |
question
What is is measured in square meters? |
answer
area |
question
What is one N/m^2? |
answer
Pascal |
question
What is the Pascal the SI unit for? |
answer
unit for pressure |
question
How many Pascals are in one atmosphere? |
answer
101325 |
question
How many inches of Hg are in one atm? |
answer
29.92 |
question
How many pounds per square inch are in one atm? |
answer
14.7 |
question
What is Boyle's Law? |
answer
P1V1=P2V2 |
question
What are gases that obey the gas laws termed? |
answer
ideal gases |
question
What make gases deviate from ideal gas behavior? |
answer
high pressure and low temperature (makes them closer together) |
question
Who was the first to fill a balloon with hydrogen gas and first to make a solo balloon flight? |
answer
Jacques Charles |
question
What is Charles' Law? |
answer
V1/T1=V2/T2 |
question
The volumes of all gases extrapolate to what? |
answer
0K or -273.15C |
question
What is Avogadro's Law? |
answer
V1/n1=V2/n2 |
question
What is the ideal gas law? |
answer
Pv=nRT |
question
Pressure units |
answer
atm |
question
volume units |
answer
liters |
question
temp units |
answer
Kelvin |
question
What is the molar volume of one mole of a gas at STP? |
answer
22.4L |
question
What is the molar mass formula? |
answer
dRT/P |
question
for a mixture of gases in a container, the total pressure exerted is the sum of the pressures that each gas in a mixture of gases in a container depends on the number of moles of that gas |
answer
Dalton's Law of Partial Pressure |
question
What is made from sodium azide? |
answer
airbags |
question
balance the decomposition of sodium azide |
answer
2NaN3->2Na+3N2 |
question
What do laws do? |
answer
summarize observed behavior |
question
What do theories do? |
answer
explain why |
question
When are models considered successful? |
answer
if i explains the observed behavior in question and predicts correctly the result of future experiments |
question
Why is the volume of an individual particle assumed to be zero? |
answer
particles are so small compared with distances between them |
question
What are the causes of pressure exerted by the gas? |
answer
particles are in constant motion so collisions of the particles with walls are the causes |
question
particles are assumed to exert nor forces on each other |
answer
they are assumed neither to attract nor repel each other |
question
What is assumed to be directly proportional to the Kelvin temp of the gas (ideal not real) |
answer
average kinetic energy of a collection of gas particles |
question
What is the root mean square velocity formula? |
answer
square root of 3RT/M |
question
What are the units for root mean square velocity? |
answer
m/s |
question
What is the value for R in the root mean square velocity formula? |
answer
8.3145 J/molK |
question
What is the si unit for energy |
answer
Joule |
question
What is the average distance a particle travels between collisions in a particular gas sample |
answer
mean free path |
question
What is the ration of the number of moles of a given component in a mixture both total number of moles in the mixture? |
answer
mole fraction |
question
mixing of gases |
answer
diffusion |
question
passage of a gash through a tiny orifice into a vacuum |
answer
effusion |
question
rate of the mixing of gases |
answer
rate of diffusion |
question
measure the speed at which the gas is transferred into the chamber |
answer
rate of effusion |
question
What is the formula for Graham's law of effusion? |
answer
Rate of effusion for gas 1/rate of effusion for gas 2 square root of M2/ square root of M1 |
question
Who developed an equation for real gases? |
answer
Johannes van der Waals |
question
layer of atmosphere closest to earth with all clouds and weather |
answer
troposphere |
question
What are the two main sources of pollution? |
answer
transportation and production of electricity |
question
Would gases act more ideally with a few moles involved or a great number of moles involved? |
answer
few, gases don't like to be close together |
question
One mole of gas contains how many molecules? |
answer
6.02x10^23 |
question
One mole of any gas occupies how many liters at STP? |
answer
22.4 |
question
Diatomic molecules exhibit what kind of bonding? (share electrons equally) |
answer
non polar covalent |
question
Which of the following gases diffuse faster? Oxygen gas or Butane gas? Why? |
answer
Oxygen, mass of oxygen is less than mass of butane |
question
average kinetic energy |
answer
temperature |
question
If all the gases have the same temperature, what happens? |
answer
they all have the same kinetic energy |
question
If volume increases on a gas, what happens to pressure? |
answer
decreases (Boyle's Law) |
question
Gases act most ideally under what conditions? |
answer
high temperature and low pressure |
question
What factor is used to determine if gases have the same partial pressures? |
answer
moles |
question
Would a gas exert greater pressure as an ideal gas or as a real gas? |
answer
ideal gas (postulates) |