Question 1

Which of the following molecules has the lowest boiling point?

Accepted Answer

Molecule A (CH4) has the lowest boiling point because it is the smallest molecule with the weakest van der Waals forces among the options.

Question 2

The vapor pressure of a given liquid will increase if

Accepted Answer

According to the Clausius-Clapeyron equation, the vapor pressure of a liquid is directly proportional to the temperature. Therefore, when the temperature is increased, the vapor pressure also increases.

Question 3

On a relative basis,the weaker the intermolecular forces in a substance are,

Accepted Answer

Weaker intermolecular forces result in higher vapor pressure at a given temperature. This is because weaker forces allow molecules to escape the liquid phase more easily, leading to a higher concentration of gas molecules in the vapor phase and therefore a higher vapor pressure. The other choices are not necessarily true and do not follow the trend of weaker intermolecular forces.

Question 4

Equilibrium is established between a liquid and its vapor when

Accepted Answer

Equilibrium is a dynamic process where the rate of the forward and reverse reactions are equal. In this case, the forward reaction is evaporation and the reverse reaction is condensation. At equilibrium, the rate of evaporation equals the rate of condensation, hence choice A is the best answer. Choices B, C, and D are incorrect because they do not involve dynamic equilibrium, and choice E is incorrect because it suggests that the system has reached a state of no change, which is not the case for equilibrium.

Question 5

Which of the following has the greatest boiling point?

Accepted Answer

The answer of Which of the following has the greatest...

Question 6

Ammonia (NH₃)is used as a refrigerant.At its boiling point of -33 °C,the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol.How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

Accepted Answer

The answer of Ammonia (NH₃)is used as a refrigerant.At its...

Question 7

At its boiling point of 58.8 °C,2.82 kJ of heat is required to vaporize 15.0 g of bromine (Br₂).What is the molar enthalpy of vaporization of bromine?

Accepted Answer

The answer of At its boiling point of 58.8 °C,2.82...

Question 8

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Accepted Answer

London dispersion forces are a type of van der Waals force that exist between all molecules, regardless of their polarity. However, choice B (NH₃) seems to be a typographical error and does not represent a real chemical substance. Given the context, it's likely meant to represent NH3 (ammonia), which primarily relies on hydrogen bonding rather than London dispersion forces due to the presence of a highly electronegative nitrogen atom bonded to hydrogen. Hydrogen bonding is a much stronger intermolecular force than London dispersion forces, significantly affecting the boiling point of NH3.

Question 9

Arrange Cl₂,ICl,and Br₂ in order from lowest to highest boiling point.

Accepted Answer

Boiling points increase with molecular weight and polarity. Cl2 and Br2 are nonpolar and their boiling points increase with molecular weight (Cl2 < Br2). ICl is polar and has a higher boiling point than both.

Question 10

Which of the following nonpolar molecules has the highest boiling point?

Accepted Answer

CS₂ has the highest boiling point due to its larger molecular size and greater London dispersion forces compared to the other smaller nonpolar molecules listed.

Question 11

List all the intermolecular forces present in pure acetone.

Accepted Answer

The answer of List all the intermolecular forces present in...

Question 12

Which of the following liquids has the lowest enthalpy of vaporization?

Accepted Answer

The lower the enthalpy of vaporization, the easier it is for a liquid to evaporate. As the molecular weight (MW) of a liquid increases, the enthalpy of vaporization typically increases as well. The MW of the liquids in the options increases from A to E. Therefore, option A with the lowest MW will have the lowest enthalpy of vaporization.

Question 13

Which of the following liquids would you expect to have the lowest vapor pressure at room temperature?

Accepted Answer

The higher the boiling point of a liquid, the lower its vapor pressure at room temperature. Ethylene glycol has a boiling point of 198°C, which is significantly higher than the other choices, making it the liquid with the lowest vapor pressure at room temperature.

Question 14

The molecules in solid CO₂ are attracted to each other by ___.

Accepted Answer

Solid CO₂ is a polar molecule, meaning it has a partial positive and negative charge. The polar nature of the molecule allows it to have dipole-dipole interactions between neighboring molecules. Additionally, the molecule is relatively large and has a high number of electrons, allowing it to experience London dispersion forces. Therefore, the molecules in solid CO₂ are attracted to each other by London dispersion forces and dipole-dipole interactions. Hydrogen bonding is not present in this molecule because it does not have hydrogen atoms bonded to more electronegative elements such as oxygen, nitrogen, or fluorine.

Question 15

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of methanol ( CH₃OH)in water?

Accepted Answer

Methanol contains a hydroxyl group (-OH), which can participate in hydrogen bonding with water molecules. Hydrogen bonding is a strong intermolecular force that allows for the solubility of methanol in water.

Question 16

Which of the following compounds has a boiling point closest to that of argon?

Accepted Answer

F₂ (F2) has a boiling point closest to that of argon because both are nonpolar molecules with similar molar masses, leading to similar van der Waals forces and boiling points.

Question 17

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of argon (Ar)in water?

Accepted Answer

Argon is a noble gas with a nonpolar molecule, so it does not form hydrogen bonds or dipole-dipole interactions. The solubility of argon in water is mainly due to dipole-induced dipole forces, where the polar water molecules induce a temporary dipole in the argon atoms.

Question 18

For which of the following pure solids is it necessary to break covalent bonds to make a liquid or gas: C(graphite),CO₂(s),C₆₀(s),and C(diamond)?

Accepted Answer

Both C(graphite) and C(diamond) are pure covalent solids composed entirely of carbon atoms bonded together in a network of covalent bonds. Breaking these bonds is necessary to transition from a solid to a liquid or gas. CO₂(s) and C₆₀(s) are both molecular solids held together by intermolecular forces such as London dispersion forces and dipole-dipole interactions. These forces can be overcome by increasing temperature and/or decreasing pressure to convert the substance to liquid or gas without breaking covalent bonds.

Question 19

Which of the following is the strongest intermolecular force present in NH₃?

Accepted Answer

The molecule NH₃ has hydrogen bonding present between the N-H and S=O groups, which is a stronger intermolecular force than London dispersion (A), Debye force (C), and ion-dipole interactions (D). Therefore, choice B, hydrogen-bonding, is the strongest intermolecular force present in this molecule.

Question 20

Which of the following molecules has the lowest boiling temperature?

Accepted Answer

The answer of Which of the following molecules has the...

Quiz 12: Intermolecular Forces and Liquids

Which of the following molecules has the lowest boiling point?

The vapor pressure of a given liquid will increase if

On a relative basis,the weaker the intermolecular forces in a substance are,

Equilibrium is established between a liquid and its vapor when

Which of the following has the greatest boiling point?

Ammonia (NH₃) is used as a refrigerant.At its boiling point of -33 °C,the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol.How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

At its boiling point of 58.8 °C,2.82 kJ of heat is required to vaporize 15.0 g of bromine (Br₂) .What is the molar enthalpy of vaporization of bromine?

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Arrange Cl₂,ICl,and Br₂ in order from lowest to highest boiling point.

Which of the following nonpolar molecules has the highest boiling point?

List all the intermolecular forces present in pure acetone.

Which of the following liquids has the lowest enthalpy of vaporization?

Which of the following liquids would you expect to have the lowest vapor pressure at room temperature?

The molecules in solid CO₂ are attracted to each other by ___.

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of methanol ( CH₃OH) in water?

Which of the following compounds has a boiling point closest to that of argon?

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of argon (Ar) in water?

For which of the following pure solids is it necessary to break covalent bonds to make a liquid or gas: C(graphite) ,CO₂(s) ,C₆₀(s) ,and C(diamond) ?

Which of the following is the strongest intermolecular force present in NH₃?

Which of the following molecules has the lowest boiling temperature?

Quiz 12: Intermolecular Forces and Liquids

Which of the following molecules has the lowest boiling point?

The vapor pressure of a given liquid will increase if

On a relative basis,the weaker the intermolecular forces in a substance are,

Equilibrium is established between a liquid and its vapor when

Which of the following has the greatest boiling point?

Ammonia (NH3) is used as a refrigerant.At its boiling point of -33 °C,the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol.How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

At its boiling point of 58.8 °C,2.82 kJ of heat is required to vaporize 15.0 g of bromine (Br2) .What is the molar enthalpy of vaporization of bromine?

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Arrange Cl2,ICl,and Br2 in order from lowest to highest boiling point.

Which of the following nonpolar molecules has the highest boiling point?

List all the intermolecular forces present in pure acetone.

Which of the following liquids has the lowest enthalpy of vaporization?

Which of the following liquids would you expect to have the lowest vapor pressure at room temperature?

The molecules in solid CO2 are attracted to each other by ___.

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of methanol ( CH3OH) in water?

Which of the following compounds has a boiling point closest to that of argon?

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of argon (Ar) in water?

For which of the following pure solids is it necessary to break covalent bonds to make a liquid or gas: C(graphite) ,CO2(s) ,C60(s) ,and C(diamond) ?

Which of the following is the strongest intermolecular force present in NH3?

Which of the following molecules has the lowest boiling temperature?

Ammonia (NH₃) is used as a refrigerant.At its boiling point of -33 °C,the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol.How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

At its boiling point of 58.8 °C,2.82 kJ of heat is required to vaporize 15.0 g of bromine (Br₂) .What is the molar enthalpy of vaporization of bromine?

Arrange Cl₂,ICl,and Br₂ in order from lowest to highest boiling point.

The molecules in solid CO₂ are attracted to each other by ___.

Which of the following intermolecular forces or bonds is primarily responsible for the solubility of methanol ( CH₃OH) in water?

For which of the following pure solids is it necessary to break covalent bonds to make a liquid or gas: C(graphite) ,CO₂(s) ,C₆₀(s) ,and C(diamond) ?

Which of the following is the strongest intermolecular force present in NH₃?