Chemistry Exam 1

Which of the following forces is/are responsible for capillary action, a property of liquids? 1. attractive forces between the liquid and the capillary material. 2. surface tension of the liquid 3. viscosity of the liquid

1 and 2

Which of the following concerning the ideal gas law is/are true? 1. Pressure is directly proportional to volume when temperature and moles of gas are held constant. 2. Pressure is directly proportional to moles of gas when temperature and volume are held constant. 3. Volume is inversely proportional to temperature when the pressure and moles of gas are held constant.

2 only

A particular gas exerts a pressure of 4.79 atm. What is this pressure in units of mmHg?

3.64 x 10^3 mmHg

How many atoms are contained in a face-centered cubic unit cell?

4

The enthalpy of fusion of sodium is 2.60 kJ/mol. How many grams of sodium can be melted by adding 81.7 kJ of energy to the metal at its melting point?

7.22 x 10^2 g

A flexible vessel contains 47L of gas where the pressure is 13 atm What will the volume be when the pressure is 0.85 atm, the temperature remaining constant?

72 L

When two water molecule form a hydrogen bond, which atoms are involved in the interaction?

A hydrogen from one molecule and an oxygen from the other molecule.

Which of the following exhibits dipole-dipole attraction between molecules? A) AsH3 B) CBr4 C) SiO2 D) Cl2 E) BH3

A) AsH3

Of the following substances, only ______________ has London dispersion forces as its only intermolecular force. A) CCl4 B) SnF3 C) CH3OH D) HI E) H2O

A) CCl4

Which of the following should have the lowest boiling point? A) CF4 B) SnF3 C) C4H9OH D) HCl E) F2O

A) CF4

Which of the following has dispersion forces as its only intermolecular force? A) CH4 B) HCl C) C6H13NH2 D) NaCl E) CH3Cl

A) CH4

Of the following substances, ________ has the highest boiling point. A) H2O B) SiH4 C) Ar D) Cl2 E) BF3

A) H2O

Which of the following pure substances has the lowest normal boiling point? A) H2S B) NH3 C) H2O D) H2Te E) H2Se

A) H2S

Which of the following pure substances has the highest normal boiling point? A) HI B) HCl C) HF D) H2S E) HBr

A) HF

Elemental iodine (I2) is a solid at room temperature. What is the major attractive force that exists among different I2 molecules in the solid? A) London dispersion forces B) dipole-dipole rejections C) ionic-dipole interactions D) covalent-ionic interactions E) dipole-dipole attractions

A) London dispersion forces

Which of the following phase changes are endothermic? A) Vaporization B) Freezing C) liquefaction D) crystallization E) condensation

A) Vaporization

Which of the following processes is endothermic? A) melting of ice B) condensation of water C) deposition of carbon dioxide D) freezing of water E) condensation of ammonia

A) melting of ice

Which of the following derivatives of methane has the highest boiling point? A) CBr4 B) Cl4 C) CCl4 D) CF4 E) CH4

B) Cl4

Which explanation best describes surface tension? A) Molecules of a liquid tend to resist flow. B) Molecules at the surface of a liquid experience a net force towards the liquids interior. C) Molecules of a liquid have a very low vapor pressure. D) Molecules at the edges of a liquid adhere to the surface of the liquids container. E) Molecules of a liquid tend to form a concave meniscus.

B) Molecules at the surface of a liquid experience a net force towards the liquid's interior.

Which compound has the lowest standard enthalpy of vaporization at 25 degrees Celsius? A) C6H14 B) C8H16 C) C5H12 D) C8H18 E) C7H16

C) C5H12

Which of the following compounds has the highest normal boiling point? A) CH3CH2CH2CH3 B) CH3Cl C) CH3CH2OH D) CH3OCH3 E) CH3CH2CH3

C) CH3CH2OH

Which of the following statements concerning liquids is incorrect? A) The volume of a liquid changes very little with pressure. B) Liquids are relatively incompressible. C) Liquid molecules move slowly compared to solids. D) Non-volatile liquids have low vapor pressures at room temperature. E) The molecules of a liquid are in constant random motion.

C) Liquid molecules move slowly compared to solids.

In a phase diagram what is the name for the point furthest to the top right of the diagram?

Critical point

Which of the following compounds has the highest vapor pressure at 25 degrees Celsius? A) CH3CH2OH B) CH3CH2CH2CH3 C) CH3OCH3 D) CH3CH2CH3 E) CH3CH2CH2Cl

D) CH3CH2CH3

In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces? A) CH4 B) C5H11OH C) C6H13NH2 D) CH3OH E) CO2

D) CH3OH

Of the following substances, only _______________ has London dispersion forces as the only intermolecular force. A) CH3OH B) NH3 C) H2S D) Kr E) HCl

D) Kr

Which one of the following decreases as the strength of the attractive intermolecular forces increases? A) The heat of vaporization. B) The normal boiling temperature. C) The sublimation temperature of a solid. D) The vapor pressure of a liquid.

D) The vapor pressure of a liquid.

What types of intermolecular forces exist between HI and H2S? A) dipole-dipole and ion-dipole B) dispersion forces, dipole-dipole, and ion-dipole C) dispersion forces, hydrogen bonding, dipole-dipole, and ion-dipole D) dispersion forces and dipole-dipole E) dispersion forces, dipole-dipole, and hydrogen bonding

D) dispersion forces and dipole-dipole

When NaCl dissolves in water, aqueous Na+ and Cl- ions result. The force of attraction that exists between Na+ and H2O is called a(n) __________ interaction. A) dipole-dipole B) ion-ion C) hydrogen bonding D) ion-dipole E) London dispersion force

D) ion-dipole

Rank the following molecules in order of increasing normal boiling point: CH3CH2OH, CH3CH2CH2OH, CH3CH2OCH3. A) lowest CH3CH2CH2OH, CH3CH2OCH3, CH3CH2OH highest. B) lowest CH3CH2OH, CH3CH2OCH3, CH3CH2CH2OH highest. C) lowest CH3CH2CH2OH, CH3CH2OH, CH3CH2OCH3 highest. D) lowest CH3CH2OCH3, CH3CH2OH, CH3CH2CH2OH highest. E) lowest CH3CH2OCH3, CH3CH2CH2OH, CH3CH2OH highest

D) lowest CH3CH2OCH3, CH3CH2OH, CH3CH2CH2OH highest.

Which of the following pure substances has the lowest vapor pressure are 25 degrees Celsius? A) SbH3 B) NH3 C) PH3 D) AsH3 E) H2O

E) H2O

Which of the following molecules has hydrogen bonding as its only intermolecular force? A)HF B) H2O C)C6H13NH2 D)C5H11OH E)None, all the above exhibit dispersion forces

E) None, all the above exhibit dispersion forces

C12H26 molecules are held together by __________. A) ion-ion interactions B) hydrogen bonding C) ion-dipole interactions D) dipole-dipole interactions E) dispersion forces

E) dispersion forces

Which of the following substances will have hydrogen bonding as one of its intermolecular forces?

H H | / H-C | \ H H

The predominant intermolecular force in (CH3)2NH is ____________.

Hydrogen bonding

_________ are particularly polarizable.

Large molecules, regardless of their polarity

The intermolecular force(s) responsible for the fact that CH4 has the lowest boiling point in the set CH4, SiH4, GeH4, SnH4, is/are ______________.

London dispersion forces

What is the predominant intermolecular force in CH4?

London-dispersion forces

Equal volumes of propane, C3H8, and carbon monoxide, C, at the same temperature and pressure have the same ____________.

Number of molecules

What is the name for the following phase change? I2 (s) --> I2 (g)

Sublimination

The boiling point of a liquid is

always the temperature at which the vapor pressure equals the pressure exerted on the liquid.

When lattice points occur at the corners and center of a unit cell, the cell is called

body-centered cubic

As a gaseous element condenses, the atoms become __________________ and they have _____________ attraction for one another.

closer together, more

Under what set of conditions does HCl(g) deviate the most from idea behavior?

low temperature and high pressure

When lattice points occur only at the corners of a unit cell, the cell is called _________.

primitive cubic

Together, liquids and solids constitute ____________ phases of matter.

the condensed

The measure of the resistance to flow of a liquid is

viscosity