Having a hard time with these questions. Will provide a thumbs up if answered co

Question

Having a hard time with these questions. Will provide a thumbs up if answered correctly. Notice, some questions I wasnt able to place image. So, ignore those questions.

21.The vapor pressure of a liquid:

decreases with increasing temperature.

is independent of temperature.

is equal to one atmosphere at the normal boiling point.

cannot be measured.

22.The normal boiling point of acetic acid is 117.9°C. Which of the following is true?

A.The vapor pressure of acetic acid at 100°C is less than 760 torr.

B.The vapor pressure of acetic acid at 100°C is greater than 760 torr.

C.The vapor pressure of acetic acid at 100°C is equal to 760 torr.

D.There is insufficient information to answer the question.

23.Which of the following characteristics is common to both gases and liquids?

defined shape

defined volume

rigidity

compressibility

fluidity

24.Which of the following best describes the relationship of molecules in a liquid with those in a gas at the same temperature?

A.Molecules in the liquid are much closer together than those in the gas.

B.Molecules in the liquid have less kinetic energy than those in the gas.

C.both a and b

D.neither a nor b

25.A mass of 1.50 g H2O is sealed in an evacuated 4.50-L flask and heated to 45 °C. What mass of liquid water remains in the flask when equilibrium is established? The equilibrium vapor pressure of water at 45 °C is 71.9 mm Hg. (R = 0.08206 L·atm/mol·K)

1.21 g

1.63×10-2 g

1.48 g

0.750 g

0.294 g

26.The molar enthalpy of vaporization of NH3 is 23.3 kJ/mol at its normal boiling point of -33.3 °C. How much energy is required to evaporate 1.85 kg of ammonia at -33.3 °C?

2.53×103 kJ

43.1 kJ

3.62×103 kJ

734 kJ

2.14×104 kJ

27.The normal boiling point of bromine is 58.8 °C. Using the heat of vaporization of bromine (30.0 kJ/mol), calculate the vapor pressure of bromine at 22.5 °C. (R = 8.314 J/mol·K)

A.200 torr

B.560 torr

C.760 torr

D.664 torr

E.289 torr

28.Calculate the enthalpy of vaporization of C4H10. This compound has vapor pressures of 492 mmHg and 181 mmHg at -12.0 °C and -35.0 °C, respectively. (R = 8.314 J/mol·K)

22.5 kJ/mol

2.25×104 kJ/mol

9.75×103 kJ/mol

-152 kJ/mol

30.8 kJ/mol

29.Which of the following is the strongest intermolecular interaction?

A.covalent bonding

B.dipole-dipole interactions

C.London dispersion forces

D.hydrogen bonding

30.For small molecules, which of the following usually is the weakest intermolecular interaction?

A.covalent bonding

B.dipole-dipole interactions

C.London dispersion forces

D.hydrogen bonding

31.Hydrogen bonding plays an important role in which of the following?

A.the boiling point of water

B.the expansion of water upon freezing

C.both a and b

D.neither a nor b

32.Which of the following phase changes does not involve a solid?

A.sublimation

B.evaporation

C.melting

D.None, they all involve a solid.

33.Which one of the following types of solids has delocalized electrons inherent to its structure?

A.ionic

B.covalent network

C.molecular

D.metallic

E.crystal

34.Which one of the following types of solids has delocalized electrons inherent to its structure?

ionic

covalent network

molecular

metallic

crystal

35.Which of the following solids would be expected to display the highest melting point?

A.MgCl2

B.PCl5

C.CsCl

D.C12H22O11

E.NaCl

36.Which of the following ionic compounds is insoluble in water?

Ca3(PO4)2

NaI

Na3PO4

Na(NO3)2

Li2SO4

37.In the phase diagram below, which letter indicates the area in which the substance is a gas?

A.C

B.H

C.D

D.B

E.A

38.Which of the following statements concerning the phase diagram below is/are correct?

(1) Moving from point A to B results in a phase transition from solid to liquid.
(2) At point C, solid and liquid phases coexist at equilibrium.
(3) At point C, liquid and gas phases coexist in equilibrium.

1 and 3

2 only

3 only

2 and 3

1 and 2

39.Which of the following phase changes does not involve a liquid?

A.sublimation

B.evaporation

C.melting

D.None, they all involve a liquid.

40.An electric heater is used to supply 35.2 J of energy to a 20.0-g graphite block with an initial temperature of 21.3°C.
Determine the final temperature of the graphite. (Specific heat of graphite = 0.72 J/g °C.)

999 °C

19 °C

24 °C

2.4 °C

41.Which of the following would be an example of potential energy?

An avalanche

Chemical reaction

A new lithium battery

Diffusion

42.Consider the following heating curve for the generic substance Z.

About how much energy was added to convert all of this sample of Z from the liquid at the boiling point to the gas at the boiling point?

A.60 cal

B.80 cal

C.550 cal

D.780 cal

43.Consider the following heating curve for the generic substance Z.

Based on this heating curve, what physical state of Z is present at about 60°C?

A.gas

B.solid

C.liquid

D.solid and liquid

E.liquid and gas

Explanation / Answer

21.The vapor pressure of a liquid is dependent on the temperature and it  is equal to one atmosphere at the normal boiling point.

22.The normal boiling point of acetic acid is 117.9°C. Therefore, the vapor pressure of acetic acid at 100°C is less than 760 torr.

23. Compressibility is common for both gas and liquid.

24.At the same temperature molecules in the li*quid are much closer together than those in the gas. Kinetic energy is same for both at same temperature.

25.A mass of 1.50 g H2O is sealed in an evacuated 4.50-L flask and heated to 45 °C. The equilibrium vapor pressure of water at 45 °C is 71.9 mm Hg. (R = 0.08206 L·atm/mol)

PV= nRT ; 71.9/760 *4.5 = n0.08206*318 ; n= 71.9*4.5/(760*0.08206*318) = 323.55/19832.2608 = 0.0163 mol

= 0.0163*18 g of water is in vapour state. = 0.29365 g of water is in vapour state ~ 0.29 g

mass of liquid water remains in the flask when equilibrium is established = 1.50-0.29 = 1.21 g of liquid water.

26.The molar enthalpy of vaporization of NH3 is 23.3 kJ/mol at its normal boiling point of -33.3 °C.

for 17 gram of NH3, energy = 23.3 KJ

Thud for 1850 g of NH3, energy = 1850*23.3 / 17 KJ = 2535.6 KJ option A is approxmate.

29.the strongest intermolecular interaction is

D.hydrogen bonding

30.the weakest intermolecular interaction is

C.London dispersion forces

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.