11/22 smartbook

Calculate the density of NO2 (g) at 50°C and 0.85 atm.

1.47 g/L

How many moles of an ideal gas will occupy a volume of 33.6 L at 0°C and 1 atm?

1.50 mol

When 429 mmHg of argon, 1.2 atm of neon, and 225 mmHg of helium are mixed, what is the total pressure?

1566 mmHg

Phosphorus reacts with H2 according to the balanced equation P4(s) + 6H2(g) → 4PH3(g). What would be the final pressure in a 5.0 L reaction vessel if 6 mol hydrogen gas completely reacts with phosphorus at 298 K?

20. atm

The density of a gas is 2.49 g/L at 3.00 atm and 25°C. Calculate the molar mass of the gas.

20.3 g/mol

At STP the volume of 1 mole of an ideal gas is always equal _____ to L (given to three significant figures.). This quantity is called the standard _____ volume.

22.4 molar

What is the volume occupied by 1 mole of an ideal gas at STP?

22.4 L

The pressure exerted by a column of liquid is calculated using the equation P = hdg. What would be the height (in meters) of a bromine (density = 3.120 g/cm3) column that exerts a pressure of 1 atm? Remember that g is the gravitational constant equal to 9.80665 m/s2.

3.312 m

In a barometer, the height of the liquid column should not be unreasonably high or low. Let us compare the heights of columns containing Hg or water at sea level to account for Hg as the liquid of choice. The equation P = hdg becomes h1d1 = h2d2, when comparing the heights of 2 different liquid columns under identical conditions. If the height of a Hg (density = 13.6 g/cm3) column is 76.0 cm at sea level, what is the height of a water column at sea level?

33.9 ft

The pressure exerted by a column of liquid is calculated using the equation P = hdg. What would be the height (in meters) of a carbon tetrachloride (density = 1.584 g/cm3) column that exerts a pressure of 1 atm? Remember that g is the gravitational constant equal to 9.80665 m/s2.

6.523 m

Aqueous Na2SO3 may be used to remove SO2(g) due to the reaction: Na2SO3(aq) + SO2(g) + H2O(l) → 2NaHSO3(aq). When aqueous Na2SO3 was placed in a room containing 3.5 × 104 L of SO2-contaminated air at 25°C, the pressure changed from 0.9955 atm to 0.9900 atm. How many moles of SO2 were removed by the chemical reaction with Na2SO3(aq)?

7.9 mol

Potassium chlorate is decomposed to produce potassium chloride and oxygen gas, which is collected over water. 2KClO3(s) → 2KCl(s) + 3O2(g) What is the partial pressure of oxygen (in torr) if the total pressure at 25oC was 748.6 torr?

724.8

A small piece of Cr metal reacts with dilute HNO3 to form H2 (g), which is collected over water at 25oC in a large flask. The total pressure in the flask is 762 torr. Use the table provided to determine the partial pressure of the H2 present.

738 torr

Calculate the volume occupied by 2.0 moles of an ideal gas at 25°C and 380 mmHg.

98 L

Which of the following correctly describes an ideal gas?

A gas that obeys the gas laws under all conditions

Select all the statements that correctly describe the behavior of real gases at low temperatures.

At low T, real gas particles move with slower speeds. Real gases deviate from ideal behavior at low T. At low T, attractive and repulsive forces are significant.

Under which conditions do gases behave most ideally? Select all that apply.

At low pressures At high temperatures

A particular hydrocarbon with the empirical formula CH2 has a density is 1.84 g/L at STP. Select the correct molecular formula of the gas.

C3H6

Using postulates of kinetic molecular theory, select the statement(s) that correctly describe(s) the assumptions used to define an ideal gas as distinct from a real gas.

Gas particles do not exert attractive or repulsive forces on one another. The actual volume of the gas particles is negligible compared to the container volume.

Select all the statements that correctly describe the mole fraction of a component in a mixture.

In a mixture of gases, the partial pressure of each gas is proportional to its mole fraction. A mole fraction is dimensionless. A mole fraction can be converted to a mole percent by multiplying by 100.

Which gas behaves the least ideally?

NH3

Which of the following is the statement of Dalton's law of partial pressures?

Ptotal = ΣPi

Select all the statements that explain why real gases deviate from ideal behavior at high pressures.

The gas particles are much closer to each other. The free space for movement of gas particles decreases. The collective volume of the gas particles is significant.

How does a gas exert pressure?

The moving gas particles strike each other and the walls of the container, exerting a force.

Two tables that are equal in mass are resting on the same rug. The four legs of one table each have a 2" x 2" cross-section, while the four legs of the second table each have a 4" x 4" cross-section. Which table is exerting greater pressure on the rug?

The table with the thinner legs is exerting greater pressure.

A reaction may be carried out so that a gaseous product is collected over water. Which statement describes how to calculate the pressure due to the product gas alone?

The vapor pressure of the water must be subtracted from the barometric pressure.

A barometer, which is a device used to measure _____ pressure, consists of a vacuum tube containing a column of liquid such as mercury. The atmospheric pressure is proportional to the _____ of the liquid column.

atmospheric ; height

At constant temperature and volume, gas pressure is ______ to the number of moles in the sample.

directly proportional

The atmosphere exerts a pressure on you; however, you do not feel the pressure and you are not crushed by it. This observation is explicable because the pressure inside your body is _____ the atmospheric pressure outside.

equal to

True or false: In an open-end manometer, the difference in the heights (h) is a direct measure of the pressure in the flask.

false

The pressure in a gas arises because the particles of a gas strike each other and the walls of their container, exerting a(n) _____ . The greater the number of gas particles in a particular volume, the _____ the pressure within the gas.

force, higher

How is pressure defined mathematically?

force/area

Arrange the following gases in order of increasing density (highest density at the bottom of the list) under the conditions given. Assume that the volume of the container is not fixed. Instructions

helium at 1 atm and 273k neon at 1 atm and 273 k neon at 2 atm and 273 k neon at 2 atm and 73 k

At constant pressure and volume, the density of a gas _____ as the molar mass increases. A gas made of larger particles will have a _____ density than a gas composed of smaller particles under the same conditions of temperature and pressure.

increases; higher

Barometers and manometers are generally constructed using mercury. This because ______.

instruments containing less dense fluids would be much larger

One can consider atmospheric pressure at a particular location as arising from the force exerted by a column of air reaching from that location into space. At higher altitudes, the mass of the air in the column is _____ than the mass of the column at lower altitudes. Thus, atmospheric pressure _____ as altitude increases.

less, decreases

Atmospheric pressure arises due to the force exerted by the air above the Earth. At higher altitudes, the mass of the air above the Earth is _____ than at sea level, and atmospheric pressure therefore _____ with altitude.

less; decreases

The device in the image shown is called a ______; it is used for measuring gas pressure in a closed system.

manometer

The device shown in the image is a U-tube _____, used for measuring gas pressure in an experiment. In the closed-tube design shown, a gas in the flask will exert a pressure on the mercury column closest to it, causing the column on the left to be _____ than the column on the right.

manometer, lower

Each component in a mixture contributes a fraction to the total number of moles in the mixture. This fraction is called the _____ fraction of the component. In a mixture of gases, this fraction is proportional to the _____ pressure for each gas present.

mole, partial

The pressure exerted by each individual gas in a mixture of gases is called its _____ pressure. This pressure is proportional to the_____ fraction of the gas in the mixture.

partial, mole

The SI unit for pressure is the _____.

pascal (Pa)

Baking soda and vinegar are mixed to form carbon dioxide gas according to the reaction below; the gas is collected at 21oC in an inverted graduated cylinder over water. NaHCO3(s) + HC2H3O2(aq) → CO2(g) + H2O(l) + NaC2H3O2(aq) In order to determine the pressure of CO2 in the cylinder, the vapor pressure of water at 21oC must be ______.

subtracted from the measured barometric pressure

In the open-end manometer shown, the difference in the mercury heights (h) corresponds to ______.

the difference between the pressure in the flask and the atmospheric pressure

Dalton's law of partial pressures states that for a mixture of gases, the _____ pressure is the _____ of the partial pressures of the individual gases. (Assume that the gases do not react with each other.)

total, sum

At STP, the density of argon is _____.

twice the density of neon

What is the correct relationship between the number of moles of gas consumed and the change in pressure in the reaction vessel, at constant V and T?

Δn = ΔP(VRTVRT)

Which of the following statements about a mercury barometer are correct? Select all that apply.

-The atmospheric pressure is proportional to the height of the mercury in the tube. -The mercury tube is sealed at the top. -The barometer contains a tube filled with mercury that is inverted in a container of mercury.

The abbreviation STP indicates a temperature of _____ and a pressure of _____.

0 degrees C, 1 atm

If 1.0 mole of neon, 2.0 moles of helium, and 3.0 moles of argon are mixed, what is the mole fraction of helium?

0.33

A mixture of gases contains 1.50 mol of O2, 0.75 mol of He, and 2.25 mol of N2. The total pressure exerted by the mixture is equal to 2.50 atm. What is the partial pressure of the He?

0.418 atm

A mixture of gases contains 8.00 g of He, 29.96 g of Ar, and 48.00 g of O2. What is the mole fraction of He in this mixture?

0.471

Which temperature and pressure correspond to STP?

1 atm 0°C