Question 1

List out the general features of a phase diagram.

Accepted Answer

$\bullet$A typical phase diagram consists of discrete regions that represent the different phases exhibited by a substance. Each region corresponds to the range of combinations of temperature and pressure over which that phase is stable.
$\bullet$The lines in a phase diagram correspond to the combinations of temperature and pressure at which two phases can coexist in equilibrium. 
a. The line that connects points A and D separates the solid and liquid phases and shows how the melting point of a solid varies with pressure.
b. The line that connects points A and B is the vapor pressure curve of the liquid. It ends at the critical point, beyond which the substance exists as a supercritical fluid.
c. The line that connects points A and C is the   vapor pressure curve of the solid phase.
$\bullet$The point A represents the triple point, which is the only combination of temperature and pressure at which all three forms of matter are in equilibrium, and hence can exist simultaneously.

Question 2

What are ionic liquids? List any two applications of ionic liquids.

Accepted Answer

Ionic liquids are ionic substances that are liquid at room temperature and pressure, and consist of small, symmetrical anions, combined with larger, asymmetrical organic cations that prevent the formation of a highly organized structure.
Examples: tetrapentylammonium bromide, 1-butyl-3-methylimidazolium hexafluorophosphate
Students' answers might vary for applications.
Ionic liquids can be used to extract specific molecules from a solution. They can also be used to produce commercially important organic compounds such as, Styrofoam and Plexiglas.

Question 3

Which of the following substances has the highest critical temperature?

Accepted Answer

A)  Ammonia 
B)  Mercury 
C)  Carbon dioxide 
D)  Water 
E)  Ethanol 
A)  Ammonia 
B)  Mercury 
C)  Carbon dioxide 
D)  Water 
E)  Ethanol B

Question 4

The natural logarithm of 0.298 is _____.

Accepted Answer

A)  2.98 
B)  0.12 
C)  -1.21 
D)  -2.98 
E)  1.21 
A)  2.98 
B)  0.12 
C)  -1.21 
D)  -2.98 
E)  1.21

Question 5

The transition from a solid to a gas is exothermic, as it releases energy.

Accepted Answer

A) True 
 B)False

Question 6

Why do liquids adopt the shape, but not the volume of their containers?

Accepted Answer

The molecules in liquids are free to mov

Question 7

The enthalpy change that accompanies the conversion of a solid directly to a gas is called enthalpy of _____.

Accepted Answer

A)  combustion 
B)  sublimation 
C)  fusion 
D)  vaporization 
E)  solution 
A)  combustion 
B)  sublimation 
C)  fusion 
D)  vaporization 
E)  solution

Question 8

When solid carbon dioxide is heated, it undergoes sublimation to form a gas.

Accepted Answer

A) True 
 B)False

Question 9

Answer the questions based on the phase diagram given below
 
-The line that connects points A and B in the given phase diagram is:

Accepted Answer

A)  is the vapor pressure curve of the solid phase. 
B)  shows the melting point variation of a solid with pressure. 
C)  is the vapor pressure curve of the liquid phase. 
D)  is the vapor pressure curve of the gas phase. 
E)  shows the boiling point variation of a liquid with pressure. 
A)  is the vapor pressure curve of the solid phase. 
B)  shows the melting point variation of a solid with pressure. 
C)  is the vapor pressure curve of the liquid phase. 
D)  is the vapor pressure curve of the gas phase. 
E)  shows the boiling point variation of a liquid with pressure.

Question 10

In a phase diagram, the region that corresponds to a combination of high pressure and low temperature favors _____ phase.

Accepted Answer

A)  gas 
B)  supercritical fluid 
C)  supercooled liquid 
D)  solid 
E)  liquid 
A)  gas 
B)  supercritical fluid 
C)  supercooled liquid 
D)  solid 
E)  liquid

Question 11

Liquid crystals are isotropic.

Accepted Answer

A) True 
 B)False

Question 12

The rate of diffusion in liquids is faster than that in gases.

Accepted Answer

A) True 
 B)False

Question 13

The surface tension of a liquid is measured in units of _____.

Accepted Answer

A)  g/cm3 
B)  J/˚C 
C)  Pa·s 
D)  J/m2 
E)  J/cm2 
A)  g/cm3 
B)  J/˚C 
C)  Pa·s 
D)  J/m2 
E)  J/cm2

Question 14

An arrangement of molecules in which their properties depend on the direction they are measured is described as _____.

Accepted Answer

The answer of An arrangement of molecules in which their...

Question 15

Which of the following physical processes is a reverse of the process of sublimation?

Accepted Answer

A)  Condensation 
B)  Deposition 
C)  Fusion 
D)  Freezing 
E)  Vaporization 
A)  Condensation 
B)  Deposition 
C)  Fusion 
D)  Freezing 
E)  Vaporization

Question 16

In which of the following orientations of liquid crystals, the molecules are directionally oriented and stacked in a helical pattern, with each layer rotated at a slight angle to the ones above and below it?

Accepted Answer

A)  Critical phase 
B)  Nematic phase 
C)  Metastable phase 
D)  Smectic phase 
E)  Cholesteric phase 
A)  Critical phase 
B)  Nematic phase 
C)  Metastable phase 
D)  Smectic phase 
E)  Cholesteric phase

Question 17

In the _____ phase, the liquid crystal molecules are relatively more opaque compared to the other orientations.

Accepted Answer

A)  nematic 
B)  metastable 
C)  smectic 
D)  cholesteric 
E)  critical 
A)  nematic 
B)  metastable 
C)  smectic 
D)  cholesteric 
E)  critical

Question 18

The vapor pressure of methanol at 50.0˚C and 65.0˚C is 400.0 and 760.0 torr respectively. The enthalpy of vaporization of methanol will be _____ kJ/mol.

Accepted Answer

A)  3.89 
B)  391 
C)  38.8 
D)  107 
E)  65.0 
A)  3.89 
B)  391 
C)  38.8 
D)  107 
E)  65.0

Question 19

The natural logarithm of _____ is 2.56.

Accepted Answer

A)  12.86 
B)  12.29 
C)  13.06 
D)  12.94 
E)  13.69 
A)  12.86 
B)  12.29 
C)  13.06 
D)  12.94 
E)  13.69

Question 20

What is dynamic equilibrium? Why there is no equilibrium established in the case of a liquid in an open container?

Accepted Answer

Dynamic equilibrium is a state in which

Exam 11: Liquids

List out the general features of a phase diagram.

What are ionic liquids? List any two applications of ionic liquids.

Which of the following substances has the highest critical temperature?

The natural logarithm of 0.298 is _____.

The transition from a solid to a gas is exothermic, as it releases energy.

Why do liquids adopt the shape, but not the volume of their containers?

The enthalpy change that accompanies the conversion of a solid directly to a gas is called enthalpy of _____.

When solid carbon dioxide is heated, it undergoes sublimation to form a gas.

Answer the questions based on the phase diagram given below -The line that connects points A and B in the given phase diagram is:

In a phase diagram, the region that corresponds to a combination of high pressure and low temperature favors _____ phase.

Liquid crystals are isotropic.

The rate of diffusion in liquids is faster than that in gases.

The surface tension of a liquid is measured in units of _____.

An arrangement of molecules in which their properties depend on the direction they are measured is described as _____.

Which of the following physical processes is a reverse of the process of sublimation?

In which of the following orientations of liquid crystals, the molecules are directionally oriented and stacked in a helical pattern, with each layer rotated at a slight angle to the ones above and below it?

In the _____ phase, the liquid crystal molecules are relatively more opaque compared to the other orientations.

The vapor pressure of methanol at 50.0˚C and 65.0˚C is 400.0 and 760.0 torr respectively. The enthalpy of vaporization of methanol will be _____ kJ/mol.

The natural logarithm of _____ is 2.56.

What is dynamic equilibrium? Why there is no equilibrium established in the case of a liquid in an open container?

Introduction to Chemistry

Molecules, Ions, and Chemical Formulas

Chemical Reactions

Reactions in Aqueous Solution

Energy Changes in Chemical Reactions

The Structure of Atoms

The Periodic Table and Periodic Trends

Ionic Versus Covalent Bonding

Molecular Geometry and Covalent Bonding Models

Gases

Solids

Solutions

Chemical Kinetics

Chemical Equilibrium

Aqueous Acidbase Equilibriums

Solubility and Complexation Equilibriums

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Periodic Trends and the S-Block Elements

The P-Block Elements

The D-Block Elements

Organic Compounds

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