The Simple Gas Laws study the effect of changing pressure, temperature and moles have on the variable of volume. Together all three Simple Gas Laws combine to give the Ideal Gas Law.
Concept: Boyle's Law3m
Welcome back guys. In this new video, we get to take a look at the simple gas laws. Let's start it out. We're going to say that the first gas law states that at constant temperature, the volume occupied by a gas in a container is inversely proportional to its external pressure. What the heck does that mean?
Inversely proportional just means that they're opposite of each other. What this is really saying is volume and pressure are opposites, meaning if one goes up, let's say our volume goes up, that means that our pressure goes down. If our volume goes down, then our pressure goes up. That's all inversely proportional means.
We're going to say that the simple gas law that tells us this is Boyle's Law. If you want to see this visually, think of it like this. We have a container. Inside this container, we have this piston that pushes down. This piston represents pressure. Here we're going to say that the piston is not very low because there's not much pressure. We're going to say here pressure is very low, so pressure low. Now, all this space in here, all this free room in there is our volume. Because the pressure is low, our volume is very high. There's a lot of room.
But let's say that I decide that I want to push down on this piston. I come in, wrap my hand around it and push down. Now the pressure increases because I'm pushing down on it. As a result, look at the volume now. Pressure here would be high, as a result, volume would be very low. Pressure and volume being opposite of each other, that's Boyle's Law.
It's going to be important for you to remember these simple gas laws because professors can ask calculated questions on using Boyle's Law or they could just simply ask you a theory question, which simple gas law states that volume and pressure are opposites of each other, that they're inversely proportional. That would be an easy question to get correct, so just remember what it means. It means that pressure and volume are opposites of each other.
Boyle’s Law states that pressure and volume are inversely proportional, which basically means they are opposites, at constant moles and temperature.
Concept: Charles Law3m
The next simple gas law states that at constant pressure, the volume occupied by a gas in a container is directly proportional to its absolute Kelvin temperature. All this means is volume and your Kelvin temperature are directly related. If your volume increases, then your temperature is increasing. If your volume is decreasing, well, your temperature must be decreasing. We're going to say that this is known as Charles' Law.
If we looked at a picture of this, so let's say we have a container. Here's the volume in the container. There's no heat being supplied to this container and as a result, the volume is low and the temperature is low. But let's say I take that same container and all of the sudden I light a match underneath it and heat it up. What happens here is there are gas particles here the whole time. When I heat them up, the gas particles are going to absorb this thermal energy from the match that I let. They absorb this thermal energy and use it as fuel to make the move, so they convert thermal energy to kinetic energy. So they have more energy so they're able to bounce off things faster and harder.
They absorb this energy and they hit the top of this piston with more force, thereby pushing it up, so the piston slides up because the gases are hitting it harder. As a result, because I increase the temperature, I increase the kinetic energy of my gas particles which then increased the volume. That's how it works. That's Charles' Law. So I increased the temperature, so the temperature now is high, so volume becomes high.
Remember the connection for this is because the gas particles absorb that thermal energy and change it to kinetic energy and use it to push the piston up, thereby increasing the volume.
Charles Law states that volume and temperature are directly proportional if pressure and moles are constant. So if one is high then the other is high and vice versa.
Concept: Avogadro's Law2m
The next simple gas law states that at constant temperature and pressure, the volume of a gas is directly proportional to the amount moles of gas. Remember the SI unit for the amount of a substance is the mole. This law basically says that if my volume is increasing, it's because my moles are increasing. If my volume is decreasing, it's because my moles are decreasing. This is known as Avogadro's Law. Same guy from Avogadro's number.
This makes sense. Let's say we had only three gas particles in here. There's not that many of them, so we don't need that much room. But let's say I started pumping in way more gas particles, naturally, if I have more gas particles, I need room for them because you can't squeeze all of them into that small little space. So what do I do? I just increase the volume to fit more people in there.
Avogadro’s Law states that volume and moles are directly proportional at constant pressure and temperature. So if one is high then the other is high and vice versa.
Concept: Understanding PV = nRT, the Ideal Gas Law3m
We're going to say that Boyle's Law, Charles' Law and Avogadro's Law, each of the gas laws focuses on the effects that changes in one variable can have on the volume of a gas. So these three guys are looking to see the effects that all of these changes have on the volume of a container. We're going to say altogether they combine to give us the Ideal Gas Law. This equation is going to be essential for our calculations dealing with gases.
The Ideal Gas Law is PV = nRT. We're going to say that P here equals pressure in atmospheres. We're going to say V equals volume in liters. We're going to say that n equals our moles of the gas. T equals temperature in Kelvin. R equals our gas constant. From the name gas constant it means that it's a constant number, so it's going to be up to you guys to remember what that constant number is. R equals 0.08206. The units are liters times atmospheres over moles times K.
What you should realize is the units in R are what is telling us the other units for everyone else. The units we find in R dictate the units found in all the other units. Because R has liters, volume has to be in liters. Because R has atmospheres, pressure is in atmospheres. Moles, moles. And Kelvin, that's why temperature has to be in Kelvin. The units of R dictate the units of all the other variables.
Concept: Gay-Lussac's Law3m
Usually, professors kind of skip this other gas law because it doesn't talk about the influences that we have on volume. It relates our pressure to our temperature, which is different. We're going to say in lab is where you usually see this simple gas law. Just make reference to this. You usually see this simple gas law in lab. Just remember what this one is because it could help you in lab when you're doing calculations or have to write a report.
Here, this last gas law states that at constant volume and moles, the pressure exerted by a gas is directly proportional to the internal temperature of the container. Basically, what it's saying here, pressure and temperature, they're saying that if your pressure is increasing, it's because your temperature is increasing. If your pressure is decreasing, it's because your temperature is decreasing.
Now, why is that? Let's think about it. Here we don't have any temperature at all and we have these three gas particles. The temperature is low, so the pressure is low. But I introduce a flame. We're saying that the volume stays constant, so the volume is not going to increase. The volume stays the same. We keep the volume the same. I increase the heat. The gas particles are going to absorb that thermal energy and use it as kinetic energy. They absorb that energy, they move faster. If they're moving faster, they're going to be hitting the walls of the container harder.
Remember we said, back in the beginning, that pressure is force per area. If the gases are moving faster and hitting the walls harder, then the pressure is going to naturally increase. It can naturally increase because we're keeping the volume the same. This simple gas law is called the Gay-Lussac's Law.
Remember this one. It's different from the first three. The first three are talking about the changes that we do to the other variables and the effects they have on the volume of a gas. Here we're talking about the influences of temperature on the pressures found in the container. Different. It's still important to know because your teachers may put it on the exam or you may be asked it in lab. Definitely in lab, so it's important to remember this last one here
Gay-Lussac’s Law states that pressure and temperature are directly proportional at constant volume and moles. So if one is high then the other is high and vice versa.
Sometimes we will be given two of the same variables such as volume, temperature, pressure or moles. In these cases, you will have to learn to manipulate the Ideal Gas Law to isolate the equation you need.
Example: A sample of neon gas occupies 112 mL at 0.567atm. If the temperature remains constant, what is the volume (in L) at 1165 mmHg?6m
When manipulating the Ideal Gas Law you want your common set of variables on one side of your equation.
Example: An engineer pumps air at 0 degrees C into a mechanized piston-cylinder engine. If the volume measures 7.18 cm3 what will the new temperature be at 12.3 mL?6m
Manipulating the Ideal Gas Law can help us solve questions beyond our understanding of the Simple Gas Laws.
Problem: A large plastic container holds 47.1 g of water vapor at a pressure of 1.12 atm. What is the new pressure if 12.1 g of water vapor is removed at constant temperature?7m
If we are not given two of the same variables such as volume, temperature, pressure or moles then we just use the Ideal Gas Law.
Concept: Ideal Gas Stoichiometry3m
Welcome back guys. In this new video, we're going to attempt to relate the Ideal Gas Law to our old friend, stoichiometry.
Let's take a look here at this first part. We say in the previous chapters, we encountered reactions that involved gases. So we might be talking about gases in greater detail now, but there have been times when we dealt with gases. The first time was when we had oxygen gas as a reactant. Remember, when did we see this? We saw this in combustion.
Example we have CH4 reacting with O2 gas. That creates, remember combustion creates carbon dioxide as a gas plus water vapor. All we have to remember to do here is just balance out the equation. That would be an example where we dealt with gases in combustion.
The second time when we dealt with gases in hydrogen displacement. Hydrogen displacement we have basically a metal reacting with an acid, HCl, HBr, or HI. The metal physically kicks out the hydrogen and hydrogen exists by itself as H2 gas. An example we have magnesium solid reacting with HCl aqueous. Magnesium comes in and kicks out the hydrogen.
Remember, magnesium is going to connect with the chlorine. That's going to form an ionic compound because we're going to have a metal connected to a nonmetal. Remember for ionic compounds, we have to remember the charges. Magnesium is in group 2A, so it's plus two. Chlorine is in group 7A, so it's minus one. The two from here would come here, the one from here would move over here. We'd have MgCl2 aqueous plus, remember the hydrogen got kicked out and it can't exist by itself, so it exists as H2 gas. We just have to balance it by putting a two here and we're done.
So this is hydrogen displacement. A metal physically kicks out hydrogen from a halogen. This could also happen with HBr, HI. They also would do hydrogen displacement.
Now it's time for us to connect our Ideal Gas Law concepts that we've covered thus far plus the older concepts we learned about stoichiometry.
We’ve dealt with gases on previous topics such as stoichiometry, where the gas was either a reactant or product. Now we can relate Stoichiometry to the Ideal Gas Law.
For a stoichiometric question dealing with the Ideal Gas Law just focus on the KNOWN quantities and determine which portion of the ideal Gas Law you need to isolate.
Example: Magnesium reacts with excess hydrochloric acid to form aqueous magnesium chloride and 26.7 mL of hydrogen gas at 25 degrees C and 723 mmHg.
Mg (s) + 2 HCl (aq) → MgCl2 (aq) + H2 (g)
How many grams of magnesium reacted?6m
When a gas is collected over water the total pressure is the partial pressures of the gas and of water vapor. To determine the correct answer you need to find the partial pressure of only the gas.
Example: Acetylene (C2H2), an important fuel in wielding, is produced in the laboratory when calcium carbide (CaC2) reacts with water:
CaC2 (s) + 2 H2O (l) → C2H2 (g) + Ca(OH)2 (aq)
The pressure of acetylene collected over water is 729 torr while the volume was measured as 629 mL. If at 21 degrees C the vapor pressure of the water is 29 torr, how many grams of acetylene were produced?6m
Enter your answer in the provided box.
Given that 8.33 moles of carbon monoxide gas are present in a container of volume 26.10 L, what is the pressure of the gas (in atm) if the temperature is 47°C?
Enter your answer in thr provided box.
What is the volume of 5.37 moles of an ideal gas at 35.5°C and 1.00 atm?
0.976 mol sample of helium gas at a temperature of 24.0°C is found to occupy a volume of 21.2 liters. The pressure of this gas sample is ___ mm Hg.
A sample of helium gas collected at a pressure of 0.976 atm and a temperature of 24.0°C is found to occupy a volume of 21.2 liters. How many moles of He gas are in the sample?
A sample of argon gas collected at a pressure of 0.702 atm and a temperature of 291 K is found to occupy a volume of 653 millimeters. How many moles of Ar gas are in the sample?
Enter your answer in the provided box.
Given that 5.31 moles of carbon monoxide gas are present in a container of volume 12.10 L, what is the pressure of the gas (in atm) if the temperature is 55 °C?
Automobile airbags contain solid sodium azide, NaN3, that reacts to produce nitrogen gas when heated, thus inflating the bag.
2NaN3 (s) → 2Na (s) + 3N2 (g)
Calculate the value of work, w, for the following system if 33.2 g of NaN3 reacts completely at 1.00 atm and 22 °C.
the volume, in liters, occupied by 1.70 moles of N2 gas
V = _______ L
the number of moles of CO2 in 3.80 L of CO2 gas
v = _______ mol
Calcium carbonate, CaCO3(s), decomposes upon heating to give CaO(s) and CO2(g). A sample of CaCO3 is decomposed, and the carbon dioxide is collected in a sealed 250 mL flask. After the decomposition is complete, the gas has a pressure of 1.6 atm at a temperature of 31 °C. How many moles of CO2 gas were generated? (Ideal gas equation: PV = nRT.)
A 9.40-L container holds a mixture of two gases at 15°C. The partial pressures of gas A and gas B. respectively, are 0.327 atm and 0.665 atm. If 0.210 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?
Enetr your answer in the provided box.
A sample of nitrogen gas in a 2.7-L container at a temperature of 17°C exerts a pressure of 5.1 atm. Calculate the number of moles of gas in the sample.
A 22.4 L high pressure reaction vessel is charged with 0.3910 mol of iron powder and 1.20 atm of oxygen gas at standard temperature. On heating, the iron and oxygen react according to the balanced reaction below.
4Fe (s) + 3O2 (g) → 2Fe2O3 (s)
After the reaction vessel is cooled, and assuming the reaction goes to completion, what pressure of oxygen remains?
A weather balloon is inflated to a volume of 30.0 L at a pressure of 742 mmHg and a temperature of 29.9°C. The balloon rises in the atmosphere to an altitude where the pressure is 380. mmHg and the temperature is -13.6°C.
Assuming the balloon can freely expand, calculate the volume of the balloon at this altitude.
At what temperature do 0.026695 mol of Ne in a 893.7 mL container exert a pressure of 0.90 atm?
An automobile tire has a maximum rating of 38.0 psi (gauge pressure).
The tire is inflated (while cold) to a volume of 11.8 L and a gauge pressure of 36.0 psi at a temperature of 120°C. While driving on a hot day the tire warms to 65.0°C and its volume expands to 12.2 L.
What is the pressure in the tire after warming on a hot day? Express your answer in pound-force per square inch to 3 significant figures.
How many grams of CO2 are contained in 550 mL of the gas at STP?
a. 1.08 g
b. 0.28 g
c. 1080 g
d. 0.56 g
e. 0.125 g
How many grams of CO2 are contained in 550 mL of the gas at STP?
b. 0.28 g
c. 1080 g
d. 0.56 g
e. 0.125 g
A sample of argon gas at STP occupies 34.0 L. What mass of argon is present in the
A sample of oxygen was collected over water at 25°C and 0.852 atm. If the total sample volume was 2.950 L, how many moles of O2 were collected?
To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 1.1-L bulb, then filled it with the gas at 1.90 atm and 24.0°C and weighed it again. The difference in mass was 2.3 g. Identify the gas.
Express your answer as a chemical formula.
If 4.33 moles of an ideal gas has a pressure of 3.14 atm, and a volume of 76.85 L, what is the temperature of the sample in degrees Celsius?
If 29.5 mol of an ideal gas occupies 13.5 L at 79.00°C, what is the pressure of the gas?
If 7.72 motes of an ideal gas has a pressure of 2.78 atm, and a volume of 33.67 L, what is the temperature of the sample in degrees Celsius?
An 8.85 L tire contains 0.525 mol of gas at a temperature of 319 K. What is the pressure (in atm) of the gas in the tire?
Express your answer with the appropriate units.
What is the temperature of 0.43 mol of gas at a pressure of 1.0 atm and a volume of 11.7 L?
Express your answer using two significant figures.
For 2SO2 (g) + O2 (g) ⇌ 2SO3 (g), Kp = 3.0 x 10 4 at 700 K. In a 2.00-L vessel the equilibrium mixture contains 1.18 g of SO3 and 0.107 g of O2.
How many grams of SO2 are in the vessel?
Express your answer using two significant figures.
A sample of carbon dioxide is contained in a 125.0 mL flask at 0.973 atm and 19.0°C. How many molecules of gas are in the sample?
lf 8.28 moles of an ideal gas has a pressure of 1.57 atm, and a volume of 87.35 L, what is the temperature of the sample in degrees Celsius?
What volume is occupied by 0.968 mol of CO2 at 274.7 K and 743 mmHg?
If 2.69 moles of an ideal gas has a pressure of 1.12 atm, and a volume of 49.85 L, what is the temperature of the sample in degrees Celsius?
The combustion of octane, C8H18, proceeds according to the reaction
2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(l)
If 305 mol of octane combusts, what volume of carbon dioxide is produced at 35.0°C and 0.995 atm?
Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq), as described by the chemical equation
MnO2(s) + 4HCl(aq) → MnCl2(aq) + 2H2O(l) + Cl2(g)
How much MnO2 (s) should be added to excess HCI(aq) to obtain 235 ml of Cl2(g) at 25°C and 715 Torr?
What pressure is exherted by 0.350 moles of carbon dioxide gas in a 2.25 L flask at 94.0 C?
lf 88.5 mol of an ideal gas occupies 86.5 L at 17.00 °C, what is the pressure of the gas?
In some aquatic ecosystems, nitrate (NO3-) is converted to nitrite (NO2-), which then decomposes to nitrogen and water. As an example of this second reaction, consider the decomposition of ammonium nitrite:
NH4NO2 (aq) → N2 (g) + 2H2 O (l)
What would be the change in pressure in a sealed 10.0 L vessel due to the formation of N 2 gas when the ammonium nitrite in 2.40 L of 1.340 M NH4NO2 decomposes at 25 °C?
What volume is occupied by 21 g of methane (CH4) at 27°C and 1.25 atm?
b. not enough data to calculate
c. 2.3199999999999998 L
d. 37.2 L e. 25.800000000000001 L
If 75.5 mol of an ideal gas occupies 88.5 L at 71.00 °C, what is the pressure of the gas?
If an ideal gas has a pressure of 4.29 atm, a temperature of 457 K, and has a volume of 60.27 L, how many moles of gas are in the sample?
At what temperature will 2.55 mole of an ideal gas in a 1.30 L container exert a pressure of 1.10 atm?
A 5.00 L flask contains 3.50 g of sulfur trioxide, 2.45 g of carbon monoxide, and 3.99 g of argon all at 35 °C. What is the pressure (in atm) in the flask?
A 8.20-L container holds a mixture of two gases at 31° C. The partial pressures of gas A and gas B, respectively, are 0.327 atm and 0.546 atm. If 0.100 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?
If 60.5 moles of an ideal gas is at 9.89 atm at 47.00 °C, what is the volume of the gas?
A sealed container holding 0.0255 L of an ideal gas at 0.993 atm and 73°C is placed into a refrigerator and cooled to 43°C with no change in volume. Calculate the final pressure of the gas.
If an ideal gas has a pressure of 2.93 atm, a temperature of 46.46oC and has a volume of 62.65 L, how many moles of gas are in the sample?
Assume that a single cylinder of an automobile engine has a volume of 525 cm3. If the cylinder is full of air at 73 ° C and 0.990 atm, how many moles of O2 are present? (The mole fraction of O2 in dry air is 0.2095.)
n = _________ mol
How many grams of C8H18 could be combusted by this quantity of O2, assuming complete combustion with formation of CO2 and H2O? m = _____________ g
A 50.0 L tank contains nitrogen gas at a pressure of 50.0 psi at 22°C. How many grams of nitrogen gas are in the tank? Do not include the units in your submitted answer.
In the metallurgical process of refining nickel, the metal is first combined with carbon monoxide to form tetracarbonylnickel. which is a gas at 43°C:
Ni(s) + 4CO(g) → Ni(CO)4(g)
This reaction separates nickel from other solid impurities. Starting with 67.4 g of Ni, calculate the pressure of Ni(CO)4 in a container of volume 5.95 L. (Assume the above reaction goes to completion.)
A 2.45-L flexible flask at 15 C contains a mixture of N2, He, and Ne at partial pressures of 0.283 atm for N2, 0.151 atm for He, and 0.425 atm for Ne. (a) Calculate the total pressure of the mixture. atm (b) Calculate the volume in liters at STP occupied by He and Ne if the N2 is removed selectively. L
How many grams of helium are contained in a 2.0 L balloon at 30.0 ° C and at 735 mmHg?
a. 66.1 g
b. 26.5 g
c. 0.477 g
d. 0.312 g
Dry ice is solid carbon dioxide, A 1.33-g sample of dry ice is placed in an evacuated 4.33 - L vessel at 21.0°C. Calculate the pressure inside the vessel after all the dry ice has been converted to CO2 gas.
A. A balloon is floating around outside your window. The temperature outside is 13 ° C, and the air pressure is 0.700 atm. Your neighbor, who released the balloon, tells you that he filled it with 4.50 moles of gas. What is the volume of gas inside this balloon? Express your answer to three significant figures and include the appropriate units.
B. A 18.0 L gas cylinder is filled with 8.00 moles of gas. The tank is stored at 49 ° C. What is the pressure in the tank? Express your answer to three significant figures and include the appropriate units.
C. A 240. L kiln is used for vitrifying ceramics. It is currently operating at 1335 °C, and the pressure is 1.075 atm. How many moles of air molecules are within the confines of the kiln? Express your answer to three significant figures and include the appropriate units.
Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25oC and 1.0 atm. R = 0.08206 Latm/molK
A sample of a gas mixture contains the following quantities of three gases. The sample has: volume = 2.50 L temperature = 16.6 degree C. What is the partial pressure for each gas, in mmHg? What is the total pressure in the flask?
The nitrogen gas in an automobile air bag, with a volume of 60. L, exerts a pressure of 858 mm Hg at 25 degree C. What amount of N_2 gas (in moles) is in the air bag?
A 0.203 g sample of carbon dioxide, CO2, has a volume of 564 mL and a pressure of 453 mmHg.
What is the temperature of the gas in kelvins? Express your answer to three significant figures.
What is the temperature of the gas in degrees Celsius? Express your answer to three significant figures.
A 7.35-L container holds a mixture of two gases at 17°C. The partial pressures of gas A and gas B, respectively, are 0.168 atm and 0.630 atm. If 0.170 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?
A mixture of oxygen and nitrogen gases is maintained in a 9.63 L flask at a pressure of 137 atm and a temperature of 15 C. If the gas mixture contains 6.66 grams of oxygen, the number of grams of nitrogen in the mixture is g.
Hyperbaric therapy uses 100% oxygen at pressure to help heal wounds and infections, and to treat carbon monoxide poisoning. A hyperbaric chamber has a volume of 1430 L. How many kilograms of O2 gas are needed to give an oxygen pressure of 3.14 atm at 25°C?
When 5.91 grams of hydrogen gas (H2) is contained in 3.75 liters at a temperature of -10.0°C, the measured pressure will be...
What is the volume occupied by 18.6 g of argon gas at a pressure of 1.19 atm and a temperature of 394 K? Express your answer with the appropriate units.
Compare the volume of 18.6 g of helium to 18.6 g of argon gas (under identical conditions).
The volume would be greater for helium gas.
The volume would be the same for helium gas.
The volume would be lower for helium gas.
Dry ice is solid carbon dioxide. A 0.050-g sample of dry ice is placed in an evacuated 4.6-L vessel at 30°C. Calculate the pressure inside the vessel after all the dry ice has been converted to CO2 gas.
What volume will 5.6 moles of sulfur hexafluoride (SF6) gas occupy if the temperature and pressure of the gas are 128°C and 9.4 atm?
Given that 6.9 moles of carbon monoxide gas are present in a container of volume 30.4 L, what is the pressure of the gas (in atm) if the temperature is 62°C?
A sample of nitrogen gas kept in a container of volume 2.3 L and at a temperature of 32°C exerts a pressure of 4.7 atm. Calculate the number of moles of gas present.
List the characteristics of an ideal gas. Write the ideal gas equation and also state it in words. Give the units for each term in the equation.
If an ideal gas has a pressure of 6.07 atm, a temperature of 10.42 °C, and has a volume of 69.83 L how many moles of gas are in the sample?
A sample of an ideal gas has a volume of 3.60 L at 14.40 C and 1.80 atm. What is the volume of the gas at 24.20°C and 0.988 atm?
If 3.63 moles of an ideal gas has a pressure of 1.25 atm, and a volume of 77.29 L. What is the temperature of the sample in degrees Celsius?
A sample of carbon dioxide is contained in a 125.0 mL flask at 0.943 atm 17.4 degree C. How many molecules of gas are in the sample?
What pressure will 14.0 g of CO exert in a 3.5 L container at 75 degrees Celsius?
What pressure (in atm) will 0.44 moles of CO2 exert in a 2.6 L container at 25oC?
What mass of NO2 is contained in a 13.0 L tank at 4.58 atm and 385 K?
Assume the ideal gas constant, R, has a value of .08206 (L * atm)/(mol * K). Convert this value into expressions for R in terms of J/(mol* K), (cubic meters * Pa)/(mol * K), (L * bar)/(mol * K), and J/(molecule * K).
A 1.00 L flask is filled with 1.00 g of argon at 25°C. A sample of ethane vapor is added to the same flask until the total pressure is 1.250atm .
What is the partial pressure of argon, PAr, in the flask? Express your answer to three significant figures and include the appropriate units.
PAr = _________________
What is the partial pressure of ethane, Pethane, in the flask? Express your answer to three significant figures and include the appropriate UNITS.
A 1.00 L flask is filled with 1.05 g of argon at 25 °C . A sample of ethane vapor is added to the same flask until the total pressure is 1.450 atm. What is the partial pressure of argon, PAr , in the flask? What is the partial pressure of ethane, Pethane, in the flask?
A mixture of oxygen gas, nitrogen gas, and carbon dioxide in a 10.0 L container at 25°C has a total pressure of 12.5 atm. If there are 30.0 g each of oxygen and nitrogen, how many grams of carbon dioxide are present?
Samples containing equal numbers of moles of H 2, N2, O2, and He are placed into separate 1 L containers at the same temperature. Assuming each gas behaves ideally, which container has the highest pressure?
e. All the gases would all exhibit the same pressure.
How many moles of O2 will be present in a 3.00 L sample of the gas collected at 25°C and 0.900 atm?
1. 0.110 mol
2. 0.134 mol
3. 83.9 mol
4. 9.06 mol
5. 1.32 mol
A mixture of He and O 2 is placed in a 4.00 L flask at 32°C. The partial pressure of the He is 2.7 atm and the partial pressure of the O2 is 1.4atm. What is the mole fraction of O 2?
Into a 5.00 L container at 18oC are placed 0.200 mol H2, 20.0 g CO2, and 14.00 g O2. Calculate the total pressure in the container and the partial pressure of each gas.
A 40.2 L constant volume cylinder containing 2.21 mol He is heated until the pressure reaches 4.20 atm. What is the final temperature?
A) 658 K
B) 1074 K
C) 804 K
D) 931 K
E) 258 K
A 55.0 L gas cylinder containing NO and 3.238 mol of N 2 has a total pressure of 2.14 atm at 303 K. What is the mole fraction of NO?
What pressure will 14.0 g of CO exert in a 3.5 L container at 75°C?
A) 1.1 atm
B) 2.3 atm
C) 4.1 atm
D) 6.4 atm
E) 5.0 atm
Calculate the volume occupied by 0.845 mol of nitrogen gas at a pressure of 1.37 atm and a temperature of 315 K.
Given: n = 0.845 mol, P = 1.37 atm, T = 315 K
A 750.0 mL metal bulb is filled with 0.421 g of CH 4 and an unknown mass of NH 3. If the total pressure in the bulb is 3.77 atm at 315°C, then how much NH3 is also in the bulb?
1. 2.39 grams
2. 0.00713 grams
3. 0.549 grams
4. 14.5 grams
5. 1.17 grams
6. 0.996 grams
7. 0.0323 grams
Calculate the mass, in grams, of 2.74 L of CO gas measured at 33°C and 945 mmHg (R = 0.08206 L•atm•K-1•mol-1, 1 atm = 760 mmHg).
a. 0.263 g
b. 35.2 g
c. 2.46 g
d. 3.80 g
e. 206 g
Hydrogen and oxygen gas are mixed in a 7.75 L flask at 65°C and contains 0.482 g of hydrogen and 4.98 g of oxyen. What is the partial pressure of oxygen in the flask?
a. 33.5 atm
b. 0.557 atm
c. 67 atm
d. 1.11 atm
e. 0.043 atm
The radius of a xenon atom is 1.3 X 10 –8 cm. A 100-mL flask is filled with Xe at a pressure of 1.0 atm and a temperature of 273 K. Calculate the fraction of the volume that is occupied by Xe atoms. (Hint: The atoms are spheres.)
A 118-mL flask is evacuated and found to have a mass of 97.129 g. When the flask is filled with 768 torr of helium gas at 35 °C, it has a mass of 97.171 g. Was the helium gas pure?
The air in a bicycle tire is bubbled through water and collected at 25 °C. If the total volume of gas collected is 5.45 L at a temperature of 25°C and a pressure of 745 torr, how many moles of gas were in the bicycle tire?
What is the mole fraction of oxygen gas in air (see Table 5.3)? What volume of air contains 10.0 g of oxygen gas at 273 K and 1.00 atm?
A 1.20-g sample of dry ice is added to a 755-mL flask containing nitrogen gas at a temperature of 25.0 °C and a pressure of 725 mmHg. The dry ice sublimes (converts from solid to gas) and the mixture returns to 25.0 °C. What is the total pressure in the flask?
A sample of gas has a mass of 0.555 g. Its volume is 117 ml at a temperature of 85 °C and a pressure of 753 mmHg. Find the molar mass of the gas.
Pressurized carbon dioxide inflators can be used to inflate a bicycle tire in the event of a flat. These inflators use metal cartridges that contain 16.0 g of carbon dioxide. At 298 K, to what pressure (in psi) can the carbon dioxide in the cartridge inflate a 3.45-L mountain bike tire? (Note: The gauge pressure is the difference between the total pressure and atmospheric pressure. In this case, assume that atmospheric pressure is 14.7 psi.)
What is the temperature of 0.52 mol of gas at a pressure of 1.3 atm and a volume of 11.8 L?
What is the pressure in a 15.0-L cylinder filled with 32.7 g of oxygen gas at a temperature of 302 K?
What is the volume occupied by 12.5 g of argon gas at a pressure of 1.05 atm and a temperature of 322 K? Would the volume be different if the sample were 12.5 g of helium (under identical conditions)?
For each of the items written below, state why it is wrong and write a version that is correct.
Write a correct version.
A 355 mL container holds 0.146 g of Ne gas and an unknown amount of Ar gas at 35°C, and a total pressure of 626 mmHg. Calculate the number of moles of Ar gas present.
a) 7.24 x 10 –3 mol Ar
b) 4.34 x 10 –3 mol Ar
c) 4.27 x 10 −3 mol Ar
d) 1.00 x 10 −2 mol Ar
e) 5.79 x 10 −3 mol Ar
What is the pressure in atm exerted by a mixture of 1.00 g H 2 and 5.00 g He when the mixture is contained in a volume of 5.00 L at 20.0°C?
What is the partial pressure in atm exerted by the H 2 in the gaseous mixture described in the previous question?
a) no given answer is close
If the pressure exerted by ozone, O 3, in the stratosphere is 3.0 x 10 -3 atm and the temperature is 255 K, how many ozone molecules are in one liter?
a. 6.0 x 1018
b. 6.1 x 10 22
c. 8.6 x 1019
d. 1.4 x 1018
e. 2.7 x 10 20
A 750.0 mL metal bulb is filled with 0.421 g of CH 4 and an unknown mass of NH 3. If the total pressure in the bulb is 3.77 atm at 315ºC, then how much NH3 is also in the bulb?
1. 0.0323 grams
2. 2.39 grams
3. 14.5 grams
4. 1.17 grams
5. 0.549 grams
6. 0.996 grams
7. 0.00713 grams
A sample of sodium azide (NaN 3), a compound used in automobile air bags was thermally decomposed and 15.3 mL of nitrogen gas was collected at 25°C and 755 torr. How many grams of nitrogen were collected?
e. 6.21 x 10 -4
Into a 500.0 L container at 18°C are placed 0.40 g of H 2, 20.0 g CO 2 and 14.0 g of O2. What is the partial pressure of H 2?
The Simple Gas Laws represent theories and equations that try to relate together pressure, temperature, volume and the amount of a gas when discussing their chemical properties and behaviors.
Boyle’s Law, also known as Mariotte’s Law, the Boyle-Mariotte Law or Pressure-Volume Law, states that pressure (P) and volume (V) are inversely proportionally, which basically means they are opposites of one another, at constant moles (n) and temperature (T).
This pressure-volume relationship is commonly displayed in the following example of a closed container. Pressure represents the downward force applied to the container while volume represents the free space within it.
When plotting this inverse pressure-volume relationship onto a chart you obtain the following:
The inverse relationship between pressure and volume at a constant mass for a gas at a fixed temperature is illustrated by the expression:
Boyle’s Law Formula
The Ideal Gas Law is presented as:
If moles (n) and temperature (T) are held constant then the formula simplifies into:
When dealing with two sets of data (2 pressures and 2 volumes) the Boyle’s Law formula becomes:
Now let’s use it in a practice problem.
PRACTICE: If an unknown gas were confined within a 5.15 L container at 3.20 atm, what would be the pressure if the volume were expanded to 11.23 L?
STEP 1: Identify the variables given.
STEP 2: Isolate the missing variable for the second pressure (P2).
Charles Law, also known as the Temperature-Volume Law, states that volume (V) and temperature (T) are directly proportionally as long as pressure (P) and moles (n) are held constant. This temperature-volume relationship is commonly displayed by the application and removal of heat from a closed container with a moveable piston.
Being directly proportional means that as the temperature increases then the volume would also increase. This direct temperature-volume relationship can be plotted onto a chart and provide the following:
The direct relationship between temperature and volume at constant moles and pressure is illustrated by the expression:
Charles’ Law Formula
By rearranging the Ideal Gas Law we can isolate V and T:
If moles (n) and pressure (P) are held constant then the formula simplifies into:
Incorporating the two sets of data (2 volumes, 2 temperatures) produces the Charles’ Law formula as:
PRACTICE: If a 2.2 L container filled with gas at a temperature of 18.0 °C is heated to a temperature of 38.0 °C, what is the new volume of the container (in liters)?
STEP 1: Identify the variables given.
STEP 2: Gas behavior is examined under absolute temperature conditions and so we must convert all temperatures from Celsius to Kelvin.
STEP 3: Plug the given values into Charles’ Law formula.
STEP 4: Perform cross-multiplication between the two ratios.
STEP 5: Isolate the missing variable for the second volume (V2).
Avogadro’s Law, also known as the Mole-Volume Law or Volume Amount Law, states that volume (V) and moles (n) are directly proportional as long as pressure (P) and temperature (T) are held constant. This mole-volume relationship is depicted with the addition or removal of gas molecules from a closed container with a moveable piston.
As more and more gas molecules are pumped into the container they push up against the moveable piston and thereby increase the volume inside the container. This direct mole-volume relationship can be plotted onto a chart and provide the following:
The direct relationship between the number of moles and volume at constant temperature and pressure is illustrated by the expression:
Avogadro’s Law Formula
By rearranging the Ideal Gas Law we can isolate V and n:
If temperature (T) and pressure (P) are held constant then the formula simplifies into:
Incorporating the two sets of data (2 volumes, 2 moles) produces the Avogadro’s Law formula as:
PRACTICE: How many moles will a sample of F2 gas occupy in a 2.50 L container, if 3.21 moles of F2 have a volume of 53.2 L?
STEP 1: Identify the variables given.
STEP 2: Plug the given values into Avogadro’s Law formula.
STEP 3: Perform cross-multiplication between the two ratios.
STEP 4: Isolate the missing variable for the second moles (n2).
This sometimes overlooked simple gas law, because it doesn’t involve a changing volume like the previous 3, states that pressure (P) and temperature (T) are directly proportional as long as volume (V) and moles (n) are held constant. This pressure-temperature relationship is depicted with the addition or removal of heat from a rigid, non-flexible container.
By increasing the temperature of a container the gas molecules will absorb the excess thermal energy and convert it into kinetic energy. With higher kinetic energies, the gas molecules will move faster and hit the walls of the container more frequently and with harder force. This in term leads to a higher overall pressure within the container.
This direct pressure-temperature relationship can be plotted onto a chart and provide the following:
The direct relationship between the pressure and temperature at constant volume and moles of gas is illustrated by the expression:
Gay-Lussac’s Law Formula
By rearranging the Ideal Gas Law we can isolate P and T:
If volume (V) and moles of gas (n) are held constant then the formula simplifies into:
Incorporating the two sets of data (2 pressures, 2 temperatures) produces the Gay-Lussac’s Law formula as:
PRACTICE: If an unknown gas possesses a pressure of 800 mmHg when the temperature is 20 °C, what would be its pressure (in mmHg) when the temperature is increased to 110 °C?
STEP 1: Identify the variables given.
STEP 2: Convert the Celsius values into Kelvin.
STEP 3: Plug the given variables into the Gay-Lussac’s Law Formula.
STEP 4: Perform cross-multiplication between the two ratios.
STEP 5: Isolate the missing variable for the second pressure (P2).
By combining the Simple Gas Laws we are able to create the Ideal Gas Law and the Combined Gas Law. Through these equations we can examine gas behaviors as well as their properties dealing with molar mass, partial pressure, density, effusion, speed and velocity.
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