Question 1

What statement best describes a mole?

Accepted Answer

A) a little furry mammal that lives in the ground 
B) a very small number chemists use to count atoms or molecules 
C) the amount of molecules or atoms in 1 gram of something 
D) It is a very large number chemists use to count atoms or molecules. 
E) none of the above 
A) a little furry mammal that lives in the ground 
B) a very small number chemists use to count atoms or molecules 
C) the amount of molecules or atoms in 1 gram of something 
D) It is a very large number chemists use to count atoms or molecules. 
E) none of the above

Question 2

Many solvents expand to occupy greater volumes with increasing temperature. What happens to the concentration of a solution made with such a solvent as its temperature is increased?

Accepted Answer

A) Since concentration depends on how much mass is dissolved in a given volume, as the volume increases, the concentration decreases. 
B) The concentration of a solution increases as the solute fits into the new spaces between the molecules. 
C) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has decreased. 
D) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has increased. 
A) Since concentration depends on how much mass is dissolved in a given volume, as the volume increases, the concentration decreases. 
B) The concentration of a solution increases as the solute fits into the new spaces between the molecules. 
C) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has decreased. 
D) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has increased.

Question 3

Which of the following would be considered a heterogeneous mixture?

Accepted Answer

A) salad dressing 
B) water 
C) milk 
D) vegetable oil 
E) vinegar 
A) salad dressing 
B) water 
C) milk 
D) vegetable oil 
E) vinegar

Question 4

Might reverse osmosis be used to obtain fresh water from a sugar-water solution?

Accepted Answer

A) No, osmosis and reverse osmosis only apply to aqueous solutions containing ions. 
B) Yes, reverse osmosis can be applied to any aqueous solution for the generation of fresh water. 
C) No, the molecular attractions between sugar and water are too strong. 
D) Yes, because sugar molecules are smaller than sodium or chloride ions. 
A) No, osmosis and reverse osmosis only apply to aqueous solutions containing ions. 
B) Yes, reverse osmosis can be applied to any aqueous solution for the generation of fresh water. 
C) No, the molecular attractions between sugar and water are too strong. 
D) Yes, because sugar molecules are smaller than sodium or chloride ions.

Question 5

Which of the above might best describe how soap behaves in a nonpolar solvent like turpentine?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) none of the above 
A) a 
B) b 
C) c 
D) d 
E) none of the above

Question 6

What is the special property of a semipermeable membrane that makes osmosis possible?

Accepted Answer

A) The pores in the membrane only allow water to pass through. 
B) Water only moves through the membrane in one direction. 
C) Only the ions travel through the membrane. 
D) Ions only move one way through the membrane. 
E) none of the above 
A) The pores in the membrane only allow water to pass through. 
B) Water only moves through the membrane in one direction. 
C) Only the ions travel through the membrane. 
D) Ions only move one way through the membrane. 
E) none of the above

Question 7

In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent?

Accepted Answer

A) nitrogen 
B) oxygen 
C) both 
D) neither 
E) Gases cannot form solutions. 
A) nitrogen 
B) oxygen 
C) both 
D) neither 
E) Gases cannot form solutions.

Question 8

How would you classify the following material? swimming pool water

Accepted Answer

A) homogeneous mixture 
B) heterogeneous mixture 
C) a pure element 
D) a pure compound 
E) depends on how many children have been in it 
A) homogeneous mixture 
B) heterogeneous mixture 
C) a pure element 
D) a pure compound 
E) depends on how many children have been in it

Question 9

Which of the following is a mixture?

Accepted Answer

A) air 
B) gold 
C) salt 
D) iron 
E) helium 
A) air 
B) gold 
C) salt 
D) iron 
E) helium

Question 10

Which of the following might have the lowest solubility in water?

Accepted Answer

A) CH3OH 
B) Cl2 
C) O2 
D) CH3CH3 
E) none of the above 
A) CH3OH 
B) Cl2 
C) O2 
D) CH3CH3 
E) none of the above

Question 11

Many dry cereals are fortified with iron, which is added to the cereal in the form of small iron particles. How might these particles be separated from the cereal?

Accepted Answer

A) add water and the iron particles will float to the top 
B) blend the cereal to a fine consistency and pass through a filter 
C) collect the iron filings with a magnet 
D) heat the cereal so that the iron particles melt and thereby coalesce 
A) add water and the iron particles will float to the top 
B) blend the cereal to a fine consistency and pass through a filter 
C) collect the iron filings with a magnet 
D) heat the cereal so that the iron particles melt and thereby coalesce

Question 12

What happens if you were to place a concentrated solution into a bag made of a semipermeable membrane and were to then suspend it in a very dilute solution?

Accepted Answer

A) The size of the suspended bag would decrease. 
B) The size of the suspended bag would increase. 
C) The size of the bag would not change. 
D) The solutions would eventually reach the same concentration. 
E) only c and d 
A) The size of the suspended bag would decrease. 
B) The size of the suspended bag would increase. 
C) The size of the bag would not change. 
D) The solutions would eventually reach the same concentration. 
E) only c and d

Question 13

Which has the most atoms?

Accepted Answer

A) a mole of gold 
B) a mole of helium 
C) a mole of lead 
D) All of the above have the same number of atoms. 
E) none of the above 
A) a mole of gold 
B) a mole of helium 
C) a mole of lead 
D) All of the above have the same number of atoms. 
E) none of the above

Question 14

What is the sum of the atomic masses of all the atoms in sucrose, C12H22O11?

Accepted Answer

A) 342 amu 
B) 182 amu 
C) 270 amu 
D) none of the above 
A) 342 amu 
B) 182 amu 
C) 270 amu 
D) none of the above

Question 15

Account for the observation that ethyl alcohol, C2H5OH, dissolves readily in water but dimethyl ether, CH3OCH3, which has the same number and kinds of atoms, does not.

Accepted Answer

A) The hydrogens on the dimethyl ether surround the molecule, shielding the inner atoms from interacting with the water. 
B) Because the carbons arrange themselves in a straight line, the ethanol can interact more easily with more water molecules, thus increasing its solubility. 
C) The high electronegativity of the carbon-oxygen-carbon bond on dimethyl ether creates a strong dipole charge on the ends of the molecule, making it highly soluble in water. 
D) Because dimethyl ether lacks an -OH group, it is significantly less polar than is ethyl alcohol and is not readily soluble in water. 
A) The hydrogens on the dimethyl ether surround the molecule, shielding the inner atoms from interacting with the water. 
B) Because the carbons arrange themselves in a straight line, the ethanol can interact more easily with more water molecules, thus increasing its solubility. 
C) The high electronegativity of the carbon-oxygen-carbon bond on dimethyl ether creates a strong dipole charge on the ends of the molecule, making it highly soluble in water. 
D) Because dimethyl ether lacks an -OH group, it is significantly less polar than is ethyl alcohol and is not readily soluble in water.

Question 16

If you filter sea water to remove all of the particles you would be left with a clear ________.

Accepted Answer

A) homogeneous mixture called a solution 
B) homogeneous mixture called a suspension 
C) heterogeneous mixture called a solution 
D) heterogeneous mixture called a suspension 
E) pure liquid 
A) homogeneous mixture called a solution 
B) homogeneous mixture called a suspension 
C) heterogeneous mixture called a solution 
D) heterogeneous mixture called a suspension 
E) pure liquid

Question 17

What is the molarity of 0.5 liters of a solution with five moles of sucrose in it?

Accepted Answer

A) 10 molar 
B) 0.5 molar 
C) 5 molar 
D) 2.5 molar 
E) 1 molar 
A) 10 molar 
B) 0.5 molar 
C) 5 molar 
D) 2.5 molar 
E) 1 molar

Question 18

At 10°C, which is more concentrated-a saturated solution of sodium nitrate, NaNO3, or a saturated solution of sodium chloride? (See figure shown above)

Accepted Answer

A) At 20°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl. 
B) At 10°C a saturated solution of sodium chloride, NaCl, is more concentrated than a saturated solution of sodium nitrate, NaNO3. 
C) At 10°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl. 
D) At 25°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl. 
A) At 20°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl. 
B) At 10°C a saturated solution of sodium chloride, NaCl, is more concentrated than a saturated solution of sodium nitrate, NaNO3. 
C) At 10°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl. 
D) At 25°C a saturated solution of sodium nitrate, NaNO3, is more concentrated than a saturated solution of sodium chloride, NaCl.

Question 19

Which of the following best describes a two-molar sucrose solution?

Accepted Answer

A) one liter of solution that contains 2 moles of sucrose 
B) one liter of solution that contains 2 moles of water 
C) one liter of solution that contains 6.02 × 1023 molecules of sucrose 
D) two liters of solution that contains 1 mole of sucrose 
E) one mole of sucrose dissolved in 2 liters of solution 
A) one liter of solution that contains 2 moles of sucrose 
B) one liter of solution that contains 2 moles of water 
C) one liter of solution that contains 6.02 × 1023 molecules of sucrose 
D) two liters of solution that contains 1 mole of sucrose 
E) one mole of sucrose dissolved in 2 liters of solution

Question 20

Hydrogen chloride, HCl, is a gas at room temperature. Would you expect this material to be very soluble or not very soluble in water?

Accepted Answer

A) HCl is very soluble in water by virtue of the dipole/dipole attractions occurring between the HCl and H2O molecules. 
B) It is not very soluble because it is a gas, and all gases have very low solubility in water at room temperature. 
C) HCl is very soluble in water because it is such a small molecule, there is little electrical attraction to other HCl molecules. 
D) It is not very soluble because as a gas with low density, it floats to the surface of the water and then into the surrounding atmosphere. 
A) HCl is very soluble in water by virtue of the dipole/dipole attractions occurring between the HCl and H2O molecules. 
B) It is not very soluble because it is a gas, and all gases have very low solubility in water at room temperature. 
C) HCl is very soluble in water because it is such a small molecule, there is little electrical attraction to other HCl molecules. 
D) It is not very soluble because as a gas with low density, it floats to the surface of the water and then into the surrounding atmosphere.

Exam 16: Mixtures

What statement best describes a mole?

Many solvents expand to occupy greater volumes with increasing temperature. What happens to the concentration of a solution made with such a solvent as its temperature is increased?

Which of the following would be considered a heterogeneous mixture?

Might reverse osmosis be used to obtain fresh water from a sugar-water solution?

Which of the above might best describe how soap behaves in a nonpolar solvent like turpentine?

What is the special property of a semipermeable membrane that makes osmosis possible?

In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent?

How would you classify the following material? swimming pool water

Which of the following is a mixture?

Which of the following might have the lowest solubility in water?

Many dry cereals are fortified with iron, which is added to the cereal in the form of small iron particles. How might these particles be separated from the cereal?

What happens if you were to place a concentrated solution into a bag made of a semipermeable membrane and were to then suspend it in a very dilute solution?

Which has the most atoms?

What is the sum of the atomic masses of all the atoms in sucrose, C12H22O11?

Account for the observation that ethyl alcohol, C2H5OH, dissolves readily in water but dimethyl ether, CH3OCH3, which has the same number and kinds of atoms, does not.

If you filter sea water to remove all of the particles you would be left with a clear ________.

What is the molarity of 0.5 liters of a solution with five moles of sucrose in it?

At 10°C, which is more concentrated-a saturated solution of sodium nitrate, NaNO3, or a saturated solution of sodium chloride? (See figure shown above)

Which of the following best describes a two-molar sucrose solution?

Hydrogen chloride, HCl, is a gas at room temperature. Would you expect this material to be very soluble or not very soluble in water?

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

The Atomic Nucleus and Radioactivity

Elements of Chemistry

How Atoms Bond and Molecules Attract

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: the Nature of Science

Filters

What is the sum of the atomic masses of all the atoms in sucrose, C₁₂H₂₂O₁₁?

Account for the observation that ethyl alcohol, C₂H₅OH, dissolves readily in water but dimethyl ether, CH₃OCH₃, which has the same number and kinds of atoms, does not.

At 10°C, which is more concentrated-a saturated solution of sodium nitrate, NaNO₃, or a saturated solution of sodium chloride? (See figure shown above)