3.1-3.6 Topic Question Quiz Practice

the particle volume of Ar is greater than that of Ne

Ar(g) deviates more from ideal behavior at extremely high pressures than Ne(g) does. which of the following is one reason for this difference?

see diagram

CCl4(l) is placed in a previously evacuated container at 30 degrees C, and some of the CCl4(l) evaporates. in the box below, draw a particulate diagram to show the species in the container after some of the CCl4(l) has evaporated. the phases of the species should be indicated by the spacing and distribution of the particles in the diagram. some of the species shown in the legend will not be used.

1.04 mol

CaCO3(s) --> CaO(s) + CO2(g) when heated strongly, solid calcium carbonate decomposes to produce solid calcium oxide and carbon dioxide gas, as represented by the equation above. a 2.0 mol sample of CaCO3(s) is placed in a rigid 100. L reaction vessel from which all the air has been evacuated. the vessel is heated to 898 degrees C at which time the pressure of CO2(g) in the vessel is constant at 1.00 atm, while some CaCO3(s) remains in the vessel. calculate the number of moles of CO2(g) present in the vessel at equilibrium

the pressure decreases because there are more moles of reactant gases than product gas

PCl3(g) + Cl2(g) --> PCl5(g) Kc = 0.11 a 0.60 mol sample of PCl3(g) and a 0.70 mol sample of Cl2(g) are placed in a previously evacuated 1.0 L rigid container, and the reaction represented above takes place. at equilibrium, the concentration PCl5(g) in the container is 0.040 M. as the reaction occurs at constant temperature, does the pressure inside the container increase, decrease, or remain the same? explain

the average kinetic energy of the helium atoms and neon atoms do not change when the gases are combined

a 1 L sample of helium gas at 25 degrees C and 1 atm is combined with a 1 L sample of neon gas at 25 degrees C and 1 atm. the temperature is kept constant. which of the following statements about combining the gases is correct?

about 0.20 atm, because H2 compromises 20% of the total number of moles of gas

a gas mixture at 0 degrees C and 1.0 atm contains 0.010 mol of H2, 0.015 mol of O2, and 0.025 mol of N2. assuming ideal behavior, what is the partial pressure of hydrogen gas (H2) in the mixture?

2.25 atm, because doubling the number of moles of Ar doubles its partial pressure

an equimolar mixture of N2(g) and Ar(g) is kept inside a rigid container at a constant temperature of 300 K. the initial partial pressure of Ar in the mixture is 0.75 atm. an additional amount of Ar was added to the container, enough to double the number of moles of Ar gas in the mixture. assuming ideal behavior, what is the final pressure of the gas mixture after the addition of the Ar gas?

CH4 behaves more like an ideal gas. CCl4 has greater intermolecular forces so CCl4 molecules are more attracted to each other. CCl4 has a larger electron cloud

at 400 K both compounds are gases. at this temperature, which compound, CH4(g) or CCl4(g) behaves more like an ideal gas? justify your answer, including reason about both molecules.

the partial pressure of each gas in the mixture is half its initial pressure; the final total pressure is half the sum of the initial pressure of the two gases

diagram 1 above shows equimolar samples of two gases inside a container fitted with a removable barrier placed so that each gas occupies the same volume. the barrier is carefully removed as the temperature is held constant. diagram 2 above shows the gases soon after the barrier is removed. which statement describes the changes to the initial pressure of each gas and the final partial pressure of each gas in the mixture and also indicates the final total pressure?

the strength of the intermolecular forces between the particles in the liquids

four different liquid components in flasks at 20 degrees C are represented above. the table below identifies the compounds. flask C shows the most particles in the vapor phase. which of the following is not shown in the model but best helps to explain why flask C must contain pentane?

see diagram

in the box below, draw the complete lewis electron dot diagram for PCl3

it does not show how the temporary fluctuating dipoles of the molecular electron clouds result in a net force of attraction between the molecules

the diagram above is a molecular model of a gaseous diatomic element that is just above its boiling point. intermolecular forces between the gas molecules will cause them to condense into the liquid phase if the temperature is lowered. which of the following best describes how the model is limited in its depiction of the phenomenon?

diagram A

the diagram above shows the distribution of speeds for a sample of N2(g) at 25 degrees C. which of the following graphs shows the distribution of speeds for a sample of O2(g) at 25 degrees C(dashed line)?

the gas in sample 2 would deviate more from ideal behavior because the Xe atoms are closer together, leading to an increase in intermolecular attractions

the diagrams above represent two samples of Xe gas in containers of equal volume at 280 K. which of the following correctly compares the two samples in terms of their deviation from ideal gas behavior and explains why?

liquid F2 has weak dispersion force attractions between its molecules, whereas liquid HF has both weak dispersion force attractions and hydrogen bonding interactions between its molecules

the electron cloud of HF is smaller than that of F2, however HF has a much higher boiling point than F2 has. which of the following explains how the dispersion-force model of intermolecular attraction does not account for the unusually high boiling point of HF?

the molecular masses of the gases, because the gas molecules have the same average kinetic energy and mass can be calculated using the equation KEavg = 1/2mv^2

the graph above shows the distribution of molecular speeds for four different gases at the same temperature. what property of the different gases can be correctly ranked using information from the graph, and why?

diagram 1 represents NaCl; it has a lower melting point than MgS because the coulombic attractions between its singly charged Na+ ions and the Cl- ions are weaker than those between the ions in MgS

the ionic compounds NaCl and MgS are represented by the diagrams above. which statement correctly identifies diagram 1 and identifies the compound with the lower melting point, explaining why?

boron nitride is a network solid of atoms connected by covalent bonds with fixed bond angles

the structure of one form of boron nitride is represented above. this form of boron nitride is one of the hardest substances known. which of the following best helps explain why boron nitride is so hard?

trigonal pyramidal

what is the shape of the PCl3 molecule?

CCl4 has the higher boiling point since it has a greater intermolecular force. both compounds have london dispersion forces.

which compound has a higher boiling point? justify your answer. the type(s) of intermolecular force(s) in both substances should be included in your answer.

NH3 molecules are polar while CH4 molecules are not, and the greater attractions between NH3 molecules cause the molecules to collide with the walls of the container with less force

which of the following best helps explain why the pressure of a sample of CH4(g) (molar mass 16 g/mol) is closer to the pressure predicted by the ideal gas law than a sample of NH3(g) (molar mass 17 g/mol)?

NH3 has hydrogen bonding that is stronger than the dipole-dipole forces in PH3

which statement best helps to explain the observation that NH3(l) boils at --28 degrees C, whereas PH3(l) boils at --126 degrees C?