AP Chemistry: Gases and IMFs

A sample of oxygen gas was found to effuse at a rate equal to two times that of an unknown gas. The molecular weight of the unknown gas is __________ g/mol. A) 128 B) 8.0 C) 8 D) 16 E) 64

A)

In liquids, the attractive intermolecular forces are __________. A) strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other B) not strong enough to keep molecules from moving past each other C) very weak compared with kinetic energies of the molecules D) strong enough to hold molecules relatively close together E) strong enough to keep the molecules confined to vibrating about their fixed lattice points

A)

In which of the following compounds/ions is there an exception to the octet rule? a) SF6 b) PH3 c) MgO d) BH4+1

A)

Ionic compounds are normally found in what state at room temperature? a) solid b) liquid c) gas d) none of these

A)

Properties of matter of solids liquids and gases include movement of particles. Which of the following lists matter from more movement to less movement. a)Gases>liquid>solid b)Liquid>solid>gases c)Solid>gases>liquid d)Gases>solid>liquid

A)

The Mond process produces pure nickel metal via the thermal decomposition of nickel tetracarbonyl: Ni(CO)4 (l) ¬ Ni (s) + 4CO (g). What volume (L) of CO is formed from the complete decomposition of 444 g of Ni(CO)4 at 752 torr and 22eC? A) 255 B) 20.2 C) 63.7 D) 11.0 E) 0.356

A)

The volume of a sample of gas (2.49 g) was 752 mL at 1.98 atm and 62eC. The gas is __________ A) NO2 B) SO3 C) SO2 D) Ne E) NH3

A)

According to kinetic-molecular theory, in which of the following gases will the root-mean-square speed of the molecules be the highest at 200eC? A) SF6 B) H2O C) HCl D) Cl2

B)

At 333 K, which of the pairs of gases below would have the most nearly identical rates of effusion? A) CO and CO2 B) CO and N2 C) NO2 and N2O4 D) N2O and NO2 E) N2 and O2

B)

Four identical flasks contain the following gases each at 0 degrees celsius and 1 atm pressure. Which gas has the highest density? a) He b) Cl2 c) CH4 d) NH3 e) all gases have the same density

B)

SO2 (5.0 g) and CO2 (5.0 g) are placed in a 750 mL container at 50eC. The partial pressure of SO2 in the container was __________ atm. A) 1.60 B) 2.76 C) 4.02 D) 0.192 E) 6.78

B)

The density of N2O at 1.53 atm and 45.2eC is __________ g/L. A) 0.388 B) 2.58 C) 9.99 D) 1.76 E) 18.2

B)

What is the proper definition of the dipole-dipole forces? a) Exists between nonpolar molecules and has partial positivity and negativity, stronger than ion-ion forces, needs to be close together b) Exists between polar molecules and the partial positivity and negativity, weaker than ion-ion forces, need to be close together c)Weakest of all intermolecular forces and molecules that are close together d)None of the above

B)

A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm A) 1.5 B) 15 C) 0.67 D) 3.3 E) 7.5

C)

Arrange the following gases in order of increasing average molecular speed at 25eC. Cl2, O2, F2, N2 A) Cl2 < O2 < F2 < N2 B) N2 < F2 < Cl2 < O2 C) Cl2 < F2 < O2 < N2 D) F2 < O2 < N2 < Cl2 E) Cl2 < F2 < N2 < O2

C)

On a phase diagram, the critical temperature is __________ A) the temperature required to melt a solid B) the temperature at which all three states are in equilibrium C) the temperature above which a gas cannot be liquefied D) the temperature below which a gas cannot be liquefied E) the temperature required to cause sublimation of a solid

C)

A sample of He gas (2.35 mol) occupies 57.9 L at 300.0 K and 1.00 atm. The volume of this sample is __________ L at 423 K and 1.00 atm. A) 0.709 B) 57.9 C) 41.1 D) 81.6 E) 1.41

D)

Ice is less dense than water because: a) Molecules of ice are held to each other by covalent bonding b) The molecular structure of ice is less orderly than that of water c) Ice has a molecular structure in which water molecules are arranged randomly. d) None of these

D)

The pressure in a 12.2 L vessel that contains 2.34 g of carbon dioxide, 1.73 g of sulfur dioxide, and 3.33 g of argon, all at 42eC is __________ mmHg. A) 116 B) 395 C) 134 D) 263 E) 0.347

D)

What volume (mL) of sulfur dioxide can be produced by the complete reaction of 3.82 g of calcium sulfite with excess HCl (aq), when the final SO2 pressure is 827 torr at 44eC? A) 1.39 x 10-4 B) 0.106 C) 1.00 x 10-3 D) 761 E) 578

D)

When the phase diagram for a substance has a solid-liquid phase boundary line that has a negative slope (leans to the left), the substance __________ A) sublimes rather than melts under ordinary conditions B) melts rather than sublimes under ordinary conditions C) cannot be liquefied above its triple point D) can go from solid to liquid, within a small temperature range, via the application of pressure E) cannot go from solid to liquid by application of pressure at any temperature

D)

In general, the vapor pressure of a substance increases as __________ increases. A) molecular weight B) viscosity C) hydrogen bonding D) surface tension E) temperature

E)

Sodium hydride reacts with excess water to produce aqueous sodium hydroxide and hydrogen gas: NaH (s) + H2O (l) ¬ NaOH (aq) + H2 (g) A sample of NaH weighing __________ g will produce 982 mL of gas at 28eC and 765 torr, when the hydrogen is collected over water. The vapor pressure of water at this temperature is 28 torr. A) 0.960 B) 925 C) 0.0388 D) 2.93 E) 0.925

E)

The intermolecular force(s) responsible for the fact that CH4 has the lowest boiling point in the set CH4, SiH4, GeH4, SnH4 is/are __________. A) mainly hydrogen bonding but also dipole-dipole interactions B) hydrogen bonding C) mainly London-dispersion forces but also dipole-dipole interactions D) dipole-dipole interactions E) London dispersion forces

E)

The predominant intermolecular force in CaBr2 is __________ A) hydrogen bonding B) London-dispersion forces C) ion-dipole forces D) dipole-dipole forces E) ionic bonding

E)

What two properties of real gases cause deviation from ideal behavior?

In contrast to the assumptions used for ideal gases, real molecules and atoms have finite (not zero) volumes, and they do attract one another.