Chem30A, Sum 07, Foothill College, LecExam2                         Name___________________________________

No outside paper is allowed. Use the reverse side of your answer paper as scratch. For partial points, provide supporting evidence (structure or reason) next to the answer. Total points = 35 x 4 = 140.

MULTIPLE CHOICES.  Choose the one alternative that best completes the statement or answers the question. 

1) 

A hydrogen bond is 

1) 

_________ 

A) 

an attraction between a hydrogen atom attached to N, O, or F and an N, O, or F atom. 

B) 

a bond that is stronger than a covalent bond. 

C) 

an ionic bond between H and another atom. 

D) 

the polar O-H bond in water. 

E) 

a covalent bond between H and O. 

2) 

In water, the melting point is unusually high because of 

2) 

_________ 

A) 

dispersion forces between the molecules. 

B) 

ionic bonds in the individual molecules. 

C) 

covalent bonds in the individual molecules. 

D) 

hydrogen bonding between the molecules. 

E) 

the heat content of the hydrogen-oxygen bonds. 

3) 

The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas, assuming constant temperature?  

3) 

_________ 

A) 

3.3 atm 

B) 

1.0 atm 

C) 

0.30 atm 

D) 

4.8 atm 

E) 

1.2 atm 

4) 

Which pair of molecules has the strongest dipole-dipole interactions? 

4) 

_________ 

A) 

C and C 

B) 

C and C 

C) 

N and N 

D) 

C and C 

E) 

N and C 

5) 

Which is not a correct statement of Boyle's Law? 

5) 

_________ 

A) 

 =  

B) 

For a gas sample at constant temperature, pressure and volume are inversely proportional. 

C) 

pressure α 1/volume 

D) 

pressure × volume = a constant 

E) 

none of the above 

6) 

The formation of a gas resulting from the escape of high-energy particles from the surface of a liquid is known as  

6) 

_________ 

A) 

evaporation. 

B) 

deposition. 

C) 

boiling. 

D) 

sublimation. 

E) 

melting. 

7) 

Which sample contains the largest number of atoms? 

7) 

_________ 

A) 

2.5 mol Au 

B) 

3.0 mol C 

C) 

1.5 mol NaCl 

D) 

2.0 mol C 

E) 

1.0 mol O 

8) 

At 570. mm Hg and 25°C, a gas sample has a volume of 2270 mL. What is the final pressure (in mm Hg) at a volume of 1250 mL and a temperature of 175°C? 

8) 

_________ 

A) 

470 mm Hg 

B) 

1560 mm Hg  

C) 

7000 mm Hg 

D) 

210 mm Hg 

E) 

690 mm Hg 

9) 

The process by which a semipermeable membrane allows water molecules, small molecules, and ions to pass through while retaining large particles is called 

9) 

_________ 

A) 

hydration. 

B) 

osmotic pressure. 

C) 

dilution. 

D) 

dialysis. 

E) 

solvation. 

10) 

Which representation of a methane molecule is not correct? (A methane molecule is composed of one carbon atom and four hydrogen atoms.) 

10) 

________ 

A) 

 

B) 

 

C) 

 

D) 

C 

E) 

none of the above 

11) 

A solution that has an osmotic pressure less than that of red blood cells is called 

11) 

________ 

A) 

isotonic. 

B) 

saturated. 

C) 

hypertonic. 

D) 

unsaturated. 

E) 

hypotonic. 

12) 

The VSEPR model or molecular structure requires a knowledge of ________ to predict the geometry of an atom in a molecule. 

12) 

________ 

A) 

the number of atoms bonded to the atom of interest 

B) 

the total number of atoms in the molecule 

C) 

the number of electron pairs on the atom of interest 

D) 

both A and C 

E) 

none of the above 

13) 

How many moles of neon occupy a volume of 14.3 L at STP?  

13) 

________ 

A) 

0.638 moles 

B) 

36.7 moles 

C) 

1.57 moles 

D) 

6.45 moles 

E) 

32.0 moles 

14) 

According to Henry's law, the solubility of a gas in a liquid 

14) 

________ 

A) 

decreases as the gas pressure above the liquid increases. 

B) 

increases as the gas pressure above the liquid increasees. 

C) 

depends on the liquid density. 

D) 

remains the same as the temperature increases. 

E) 

depends on the liquid polarity. 

15) 

How many grams of  are contained in a 25.0 L sample at 5.2 atm and 28.0°C? 

15) 

________ 

A) 

84.2 g 

B) 

5.26 g 

C) 

168 g 

D) 

0.164 g 

E) 

1810 g 

16) 

Which statement concerning the mole concept is not true? 

16) 

________ 

A) 

One mole of any compound contains one mole of atoms. 

B) 

One mole of sodium contains the same number of atoms as one mole of carbon. 

C) 

One mole of water contains the same number of molecules as one mole of ammonia. 

D) 

The molar mass of a metal is its atomic weight expressed in grams. 

E) 

The mole concept makes a connection between the mass of a substance and the number of particles or units of that substance. 

17) 

If the temperature of a 1.75 liter sample of gas is changed from 30.0° C to 20.0° C at constant pressure, what will be the new volume? 

17) 

________ 

A) 

1.17 L 

B) 

1.57 L 

C) 

1.69 L 

D) 

1.81 L 

E) 

2.63 L 

18) 

Which of the following is NOT part of the kinetic theory of gases? 

18) 

________ 

A) 

Gas particles do not attract or repel one another. 

B) 

There is very little empty space in a gas. 

C) 

Gas particles move faster when the temperature increases. 

D) 

Gas particles move rapidly. 

E) 

A gas is composed of very small particles. 

19) 

The carbon dioxide molecule is linear. The electronegativities of C and O are 2.5 and 3.5, respectively. Based on these values and on consideration of molecular geometry, the  is ________ and the molecule is ________. 

19) 

________ 

A) 

polar; non-polar 

B) 

non-polar; polar 

C) 

polar; polar 

D) 

non-polar; non-polar 

E) 

none of the above 

20) 

In a solution, the solvent 

20) 

________ 

A) 

is the substance present in the smallest concentration. 

B) 

is a liquid. 

C) 

can be a solid, liquid, or gas. 

D) 

can be a liquid or gas. 

E) 

is never a solid. 

21) 

What is the molarity of a solution which contains 58.5 g of sodium chloride dissolved in 0.500 L of solution? 

21) 

________ 

A) 

2.00 M 

B) 

0.500 M 

C) 

1.50 M 

D) 

1.00 M 

E) 

4.00 M 

22) 

The boiling point of water at sea level is 100°C. At higher altitudes, the boiling point of water will be  

22) 

________ 

A) 

the same, because water always boils at 100°C. 

B) 

higher, because there are fewer water molecules in the air. 

C) 

higher, because the altitude is greater. 

D) 

lower, because temperatures are lower. 

E) 

lower, because the atmospheric pressure is lower. 

23) 

Which of the following molecules can form hydrogen bonds? 

23) 

________ 

A) 

NaH 

B) 

C) 

D) 

HI 

E) 

 

24) 

The main interactions between molecules of hydrogen chloride are examples of 

24) 

________ 

A) 

dispersion forces. 

B) 

ionic bonds. 

C) 

covalent bonds. 

D) 

hydrogen bonds. 

E) 

dipole-dipole interactions. 

25) 

When the reaction shown is correctly balanced, the coefficients are

	C6H14 (l)  +  O2 (g)  →  CO2 (g)  +  H2O (g)

25) 

________ 

A) 

1, 3.5, 6, 7 

B) 

2, 19, 12, 14 

C) 

1, 6, 6, 7 

D) 

1, 9.5, 6, 7 

E) 

2, 16.5, 12, 7 

26) 

A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in mm Hg?  

26) 

________ 

A) 

7.5 mm Hg 

B) 

507 mm Hg 

C) 

1.50 mm Hg 

D) 

1140 mm Hg 

E) 

760 mm Hg 

27) 

What is the concentration, in m/m%, of a solution prepared from 50.0 g NaCl and 150.0 g of water? 

27) 

________ 

A) 

40.0% 

B) 

3.00% 

C) 

33.3% 

D) 

0.250% 

E) 

25.0% 

28) 

Determine the number of moles of water produced when one mole of N reacts according to the balanced reaction shown.
	4 N + 5   → 4 NO + 6 O

28) 

________ 

A) 

1.50 

B) 

0.67 

C) 

1.33 

D) 

1.25 

E) 

1.00 

29) 

For the dot structure shown the most likely elements are X =________ and Y = ________.

29) 

________ 

A) 

hydrogen; carbon 

B) 

fluorine; carbon 

C) 

carbon; hydrogen 

D) 

carbon; fluorine 

E) 

carbon; oxygen 

30) 

In water, a substance that ionizes completely in solution is called a 

30) 

________ 

A) 

nonconductor. 

B) 

nonelectrolyte. 

C) 

weak electrolyte. 

D) 

strong electrolyte. 

E) 

semiconductor. 

TRUE/FALSE.  Circle 'A' if the statement is true and 'B' if the statement is false. 

31) 

Steam at 100°C holds the same amount of heat as water at 100°C. 

31) 

________ 

32) 

When a liquid is boiling, its temperature does not change. 

32) 

________ 

33) 

Gas law calculations normally require the use of the Kelvin temperature scale. 

33) 

________ 

34) 

The pressure exerted by a gas on its container is inversely related to its Kelvin temperature. 

34) 

________ 

35) 

Condensation occurs when a liquid is converted to a solid. 

35) 

________ 

 

1) 

A 

2) 

D 

3) 

C 

4) 

C 

5) 

E 

6) 

A 

7) 

D 

8) 

B 

9) 

D 

10) 

B 

11) 

E 

12) 

A 

13) 

A 

14) 

B 

15) 

C 

16) 

A 

17) 

C 

18) 

B 

19) 

A 

20) 

C 

21) 

A 

22) 

E 

23) 

E 

24) 

E 

25) 

B 

26) 

D 

27) 

E 

28) 

A 

29) 

D 

30) 

D 

31) 

FALSE 

32) 

TRUE 

33) 

TRUE 

34) 

FALSE 

35) 

FALSE