genchem

Question 1

forces of attraction that exist between all atoms and molecules.

the only force present among nonpolar substances such as oxygen gas and carbon dioxide.

Answer 1

LONDON DISPERSION FORCES

Question 2

these are attractive forces between molecules.
responsible for the non-ideal behavior of gases, but they exert more influence in the condensed phases of matter which are liquids and solids

Answer 2

INTERMOLECULAR FORCES

Question 3

attractive forces between polar molecules, that is, between molecules that possess dipole moments.

the larger the dipole moment the larger the force.

Answer 3

DIPOLE-DIPOLE FORCES

Question 4

It is a special case of very strong dipole-dipole interaction.

a result of interaction between partial positive atoms (H) and the partial negative such F, O, and N.

Answer 4

HYDROGEN BONDING

Question 5

acts between an ion and a polar molecule.

the positive end of the ionic compound becomes surrounded by the partial positive ion.

Answer 5

ION-DIPOLE FORCES

Question 6

LONDON DISPERSION FORCES, DIPOLE-DIPOLE FORCES, HYDROGEN BONDING, ION-DIPOLE FORCES

Answer 6

TYPES OF INTERMOLECULAR FORCES

Question 7

LIQUIDS, SURFACE TENSION, CAPILLARY ACTION, VISCOSITY, VAPOR PRESSURE, Volatile, MOLAR HEAT OF VAPORIZATION, BOILING POINT

Answer 7

PROPERTIES OF LIQUIDS AND INTERMOLECULAR FORCES

Question 8

are made up of particles that are close to each other and have kinetic energy.

take the shape of their container and diffuse moderately to a fixed volume.

most of them exist as molecules at room temperature.

Answer 8

LIQUIDS

Question 9

is the force that causes the surface of a liquid to contract. It is the property of the surface of the liquid that allows it to resist an external force.

Answer 9

SURFACE TENSION

Question 9

is the tendency of a liquid to rise in narrow tubes or be drawn into small openings such as those between grains of rock. is a result of intermolecular attraction between the liquid and solid materials.

Answer 9

CAPILLARY ACTION

Question 9

is the intermolecular attraction between like molecules (the liquid molecules).

Answer 9

Cohesion

Question 9

is an attraction between unlike molecules (such as those in water and in the particles that make up the glass tube).

Answer 9

Adhesion

Question 10

is the resistance of fluids to flow. A liquid’s resistance (friction) to flow exists between the molecules of liquid when they move past each other. The greater the resistance in flowing, the more viscous the liquid is.

Answer 10

VISCOSITY

Question 11

is a change of state from liquid to gas, while the opposite process (gas to liquid).

when liquid molecules break free from their neighbors and escape into gas phase, the process is called vaporization.

Answer 11

VAPOR PRESSURE

Question 12

-substances that evaporate readily are _. eg, alcohol, gasoline, paint thinner and dry-cleaning solvents.

Answer 12

Volatile

Question 13

the relationship between vapor pressure and the strength of intermolecular forces is consistent with the trends in two other properties of liquids, the enthalpy or molar heat of vaporization, and the boiling point of liquid.

Answer 13

MOLAR HEAT OF VAPORIZATION

Question 14

the term solution is used to describe a homogeneous mixture in which at least one substance (solute) is dissolved in another substance (solvent).

Answer 14

Solution

Question 15

the boiling point of liquid is the temperature at which the liquid converts into a gas.

a liquid boils when its vapor pressure equals the pressure acting on the surface of the liquid. The boiling point is the temperature at which the vapor pressure of a liquid is equal to the external pressure.

Answer 15

BOILING POINT

Question 16

(also called percent by weight or weight percent) is the ratio of the mass of a solute to the mass of the solution, multiplied by 100 percent:

Answer 16

Percent by Mass

Question 17

is a common expression used for expressing concentration. It is related to the molar concentration but the difference is that the ___ ___ is expressed with a denominator of 100

Answer 17

Percent by Volume

Question 18

When the amount of solute is very small, as with trace impurities in water, concentration is often expressed in parts ___ ___

Answer 18

Percent per million

Question 19

It is a dimensionless quantity that expresses the ratio of the number of moles of one component to the number of moles of all components present. For a mixture of two substances, A and B, the mole fractions of each would be written as follows

Answer 19

Mole Fraction

Question 20

Otherwise known as “molar concentration”. It is defined as the number of moles of solute per liter of solution. The SI unit for molarity is mol/m3 ; however, you will almost always encounter molarity with the units of mol/L. A solution of concentration 1 mol/L is also denoted as “1 molar” (1 M). Mol/L can also be written in the following ways (however, mol/L, or simply M, is most common)

Answer 20

MOLARITY (M)

Question 21

It is an intensive property of solutions, and it is calculated as the moles of a solute divided by the kilograms of the solvent. Molality is the number of moles of solute dissolved in 1 kg (1000 g) of solvent—that is, (The SI unit for molality is mol/kg.

Answer 21

MOLALITY (m)