ORU Chemistry Chapter 7

If you need 10. moles of sucrose, how many liters of a 4.0 molar solution would you need? a. 2.5 L b. 0.25 L c. 25 L d. 10. L e. none of the above

A. 2.5 L

If the solubility of a compound is 72 grams per liter at a given temperature, how many grams of the compound will dissolve in 0.50 liters at the same temperature? a. 36g b. 72g c. 144g d. 30g e. none of the above

A. 36g

Which of the following is the strongest form of interatomic attraction... a. a chemical bond b. an ion-dipole interaction c. a dipole-dipole interaction d. a dipole-induced dipole interaction e. an induced dipole-induced dipole interaction

A. a chemical bond

Which of the following is the strongest form of intermolecular attraction in a water molecule? a. hydrogen bonding b. induced dipole-induced dipole c. covalent bonding d. ion-dipole e. polar-induced polar

A. hydrogen bonding

What is the main difference between a dipole-dipole interaction and a dipole-induced dipole interaction? a. both are similar, but one involves a temporary dipole created by a permanent dipole b. dipole-dipole interactions are weaker because the dipole are permanent c. dipole-induced dipole interactions are stronger because the induced dipoles can be formed at any time d. both are identical e. none of the above

A. Both are similar, but one involves a temporary dipole created by a permanent dipole

Which of the following might have the best solubility in water? a. CH3OH b. Cl2 c. O2 d. CH3CH3 e. none of the above

A. CH3OH

The separation of charges within a polar molecule is called a(n)... a. dipole b. dipole-dipole c. ionic bond d. strong attraction e. polar bond

A. Dipole

Why are the melting temperatures of most compounds far greater than the melting temperatures of most covalent compounds? a. ionic bonds are so much stronger than the intermolecular attractions between covalently bonded compounds b. covalent bonds are not as strong as ionic bonds c. as a solid, salts have a very organized crystalline structure which takes a lot of energy to break apart d. most covalent compounds have at least one weak bond in their structure that is easily broken when heat is added

A. Ionic bonds are so much stronger than the intermolecular attractions between covalently bonded compounds.

If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound? a. the ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution b. the ionic bond is weakened by the ion-dipole interactions and ionic repulsion ejects the ions from the crystal c. the ion-dipole interaction causes the ions to heat up and vibrate free of the crystal d. the ions never overcome their interatomic attraction and therefore are not soluble e. none of the above

A. The ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution

What is happening at the molecular level when a polar molecule like water interacts with a typical sodium ion? a. the water molecule aligns such that the oxygen interacts with the sodium b. the water molecule aligns such that the hydrogens interact with the sodium c. the polarity of the water molecule is altered making the oxygen more positively charged d. the polarity of the water molecule is altered making the hydrogens more negatively charged e. none of the above

A. The water molecule aligns such that the oxygen interacts with the sodium

Which of the following describes an aqueous solution? a. a mixture of some compound dissolved in water b. a mixture of polar molecules dissolved in a non polar solvent c. a mixture of water dispersed in an ionic compound d. a mixture of non polar molecules dissolved in a polar solvent e. none of the above

A. a mixture of some compound dissolved in water

What is a hydrogen bond? a. a special type of dipole-dipole attraction involving hydrogen bound to a highly electronegative atom b. a special type of dipole-dipole attraction involving hydrogen bound to any other atom c. a special type of dipole-dipole attraction involving hydrogen bound to another hydrogen atom d. a special type of attraction involving any molecules that contain hydrogens e. none of the above

A. a special type of dipole-dipole attraction involving hydrogen bound to a highly electronegative atom

A sample of steel is composed of 5 percent carbon and 95 percent iron. Which is the solvent? a. iron b. carbon c. steel d. steel is not a solution, it is a mixture e. a solid cannot be a solvent

A. iron

In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent? a. nitrogen b. oxygen c. both d. neither e. gases cannot form solutions

A. nitrogen

Which of the following best describes a two-molar sucrose solution? a. one liter of solution that contains 2 miles of sucrose b. one liter of solution that contains 2 moles of water c. one liter of solution that contains 6.02x10^23 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

Which of the following solutions is the most dilute? a. one liter of water with 1 gram of sugar b. one liter of water with 2 grams of sugar c. one liter of water with 5 grams of sugar d. one liter of water with 10 grams of sugar e. they all have the same volume

A. one liter of water with 1 gram of sugar

A dipole is a... a. separation of charges b. molecule with parallel bonds c. nonpolar entity d. form of electronegativity

A. separation of charges

In a solution made from one teaspoon of sugar and one liter of water, which is the solute? a. sugar b. water c. the teaspoon d. both sugar and water e. none of the above

A. sugar

Why might sodium carbonate (washing soda, Na2CO3) be added to hard water to aid in cleaning? a. the hard ions in water are more attracted to the carbonate ions -2 charge. b. The hard ions are dissolved by the added sodium ions c. The soap gets softer due to the added ions d. The ions solubilize the soap due to ion-ion intermolecular attraction, which improves the cleaning ability e. none of the above

A. the hard ions in water are more attracted to the carbonate ions -2 charge.

What is a molarity? a. the number of moles of solute per liter of solution b. the number of grams of solute per liter of solution c. the number of moles of solute per liter of solvent d. the number of liters of solute per liter of solvent e. none of the above

A. the number of moles of solute per liter of solution

How many molecules of sucrose are in 0.500 L of a 1.00 molar solution of sucrose? a. 3.01x10^23 molecules of sucrose b. 6.02x10^23 molecules of sucrose c. 12.04x10^23 molecules of sucrose d. 0.5 e. 1 gram

A. 3.01x10^23 molecules of sucrose

How many molecules of sucrose are in a 0.500 moles of sucrose? a. 3.01x10^23 molecules of sucrose b. 6.02x10^23 molecules of sucrose c. 12.04x10^23 molecules of sucrose d. 0.5 e. 1 gram

A. 3.01x10^23 molecules of sucrose

Which of the following molecules is most likely to show a hydrogen bonding interaction?a. CH3OH b. CH3SH c. CH4 d. H-C=-C-H e. A, B and C

A. CH3OH

How are intermolecular forces and solubility related? a. solubility depends on the solvent's ability to overcome the intermolecular forces in a solid b. solubility depends on the solutes ability to overcome the intermolecular forces in the solvent c. solubility is a measure of how strong a solvents intermolecular forces are d. solubility is a measure of how weak the intermolecular forces in the solute are e none of the above

A. solubility depends on the solvent's ability to overcome the intermolecular forces in a solid

What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution? a. 8M b. 4M c. 5M d. 2.5M

B. 4M

Which of the following describes the term concentration? a. It is what you are doing now to answer the question b. It is the amount of solute in a given amount of solution c. It is the amount of solvent in a given amount of solution d. It is the given amount of solution in a given container e. It is the given amount of solvent per amount of solute

B. It is the amount of solute in a given amount of solution

Why are ion-dipole attractions stronger than dipole-dipole attractions? a. The chemical bond in an ion-dipole molecule is similar also a covalent bond b. the magnitude of the electric charge associated with an ion is much greater c. dipole areas are subject to changing from positive to negative regions on the molecule d. like charge(dipole) does not attract like charge (another dipole)

B. The magnitude of the electric charge associated with an ion is much greater

Which of the following molecules would you expect to be the least attracted to a N+ ion? a. H-F b. H3C-CH3 c. Cl2CH2 d. F- e. HO-

B. H3C-CH3

How many molecules of sucrose are in 0.500 L of a 2.00 molar solution of sucrose? a. 3.01x10^23 molecules of sucrose b. 6.02x10^23 molecules of sucrose c. 12.04x10^23 molecules of sucrose d. 0.5 e. 1 gram

B. b. 6.02x10^23 molecules of sucrose

The charges with sodium chloride are all balanced-for every positive sodium ion there is a corresponding negative chloride ion. Since its charges are balanced, how can sodium chloride be attracted to water, and vice versa? a. dispersion forces come into plat as the sodium chloride and water come into close proximity b. hydrogen bonding in water allows the sodium chloride molecule to be attracted to the water molecule c. as a water molecule gets close to the sodium chloride it can distinguish the various ions and it is thus attracted to an individual ion by ion-dipole forces d. this is not a matter of attraction. sodium chloride dissolved in water because water provides a medium in which the individual sodium and chloride ions can disperse.

C. As a water molecule gets close to the sodium chloride it can distinguish the various ions and it is thus attracted to an individual ion by ion-dipole forces.

Describe what usually happens to a hot solution that is saturated with a solid as it cools. a. the solid that is dissolved comes out of the solution completely b. the solid stays in the solution c. some of the solid comes out of the solution d. the solution freezes e. the solution solidifies

C. Some of the solid comes out of the solution

Fluorine is a relatively... a. large atom b. soft atom c. small atoms d. greenish atom

C. small atom

Which of the following would have the lowest melting point? a. CCl4 b. CBr4 c. CF4 d. CI4 e. not enough information given

C. CF4

A soap molecule is... a. primarily polar b. primarily nonpolar c. both polar and non polar d. a neutral compound

C. both polar and nonpolar

Which of the following would have the highest boiling point? a. C6H14 b. C8H18 c. C10H22 d. C12H26 e. not enough information given

D. C12H26

List the following compounds in order of increasing boiling point: CI4, CBr4, CCl4, CF4 a. Cl4, CBr4, CCl4, CI4 b. CF4, CBr4, CCl4, Cl4 c. CI4, CCl4, CBr4, CF4 d. CF4, CCl4, CBr4, Cl4

D. CF4, CCl4, CBr4, Cl4

When you set a pot of tap water on the stove to boil, you'll often see bubbles start to form well before boiling temperature is ever reached. Explain this observation. a. these are dissolved salts heating up and excepting from the water b. these bubbles are formed as the surrounding gases from air dissolve into the water as it is heated. c. they are very minute pockets of water in the gaseous phase. When they get large enough, the water will boil as this gas escapes. d. These initial bubbles are the gases that were dissolved in the water coming out of solution. The solubility of gases in water decreases with increasing temperature.

D. These initial bubbles are the gases that were dissolved in the water coming out of solution. The solubility of gases in water decreases with increasing temperature.

The boiling point of 1, 4-butanediol is 230 degreesC. Would you expect this compound to be soluble of insoluble in room-temperature water? a. Since there are no polar areas on this molecule, it is insoluble in water at room temperature. b. a high boiling point means that the substance interacts with itself quite strongly. Therefore this molecule is not soluble in water. c. since there are polar areas on this molecule, it is insoluble in water at room temperature d. water would be attracted to both ends of 1, 4 butanediol, and it is infinitely soluble in water

D. Water would be attracted to both ends of 1, 4-butanediol, and it is infinitely soluble in water

How can you tell whether a sugar solution is saturated or not? a. add more sugar, if it dissolves, it is saturated b. there will be a precipitate if the water is heated c. as long as there are more water molecules than sugar molecules, there is a saturated solution d. add more sugar. if it does not dissolve after mixing, the solution is saturated

D. add more sugar. if it does not dissolve after mixing, the solution is saturated

In which of the following molecules will water induce a temporary dipole? a. CO2 b. O2 c. N2 d. all of the above e. none of the above

D. all of the above

Which of the following statements describes a saturated solution? a. a solution where the solvent cannot dissolve any more solute b. a solution of salt water with salt at the bottom c. a carbonated beverage with bubbles d. all of the above e. none of the above

D. all of the above

Which has the most atoms? 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

D. all of the above have the same number of atoms

Suggest why sodium chloride, NaCl, is insoluble in gasoline. Consider the electrical attractions. a. Since this molecule is so small, there is not much opportunity for the gasoline to interact with it through any electrical attractions b. Since gasoline is a very polar molecule, the salt can only form dipole-induced dipole bonds, which are very weak, giving it a low solubility in gasoline c. since gasoline is so strongly attracted to itself, the salt, NaCl is excluded d. salt is composed of ions that are too attracted to themselves. gasoline is non-polar so salt and gasoline will not interact very well.

D. salt is composed of ions that are too attracted to themselves. gasoline is non-polar so salt and gasoline will not interact very well.

Which of the following might have the lowest solubility in water? a. CH3OH b. Cl2 c. O2 d. CH3CH3 e. none of the above

D. CH3CH3

Which of the following substances is pure... a. an ionic compound consisting of sodium and chlorine ions b. a covalent compound consisting of one type of molecule c. an element D. All of the above E. non of the above

D. all of the above

Why does oxygen have such a low solubility in water? a. water's attraction for itself is stronger than its attraction for oxygen molecules b. water and oxygen only attract one another by means of weak dipole-induced dipole attractions c. the hydrogen bonding in water keeps the oxygen solubility low d. both A and B

D. both A and B

Which of the following solutions is the most concentrated? a. one liter of water with 1 gram of sugar b. one liter of water with 2 grams of sugar c. one liter of water with 5 grams of sugar d. one liter of water with 10 grams of sugar e. they all have the same volume

D. one liter of water with 10 grams of sugar

Which of the following molecules is most likely to show a dipole-dipole interaction? a. CH3OH b. CH3SH c. CH4 d. H-C=-C-H e. A and B

E. A and B

When municipal water treatment plants are not available, which of the following methods of purification might be utilized? a. chemical purification with chlorine b. reverse osmosis c. chemical purification d. boiling e. C and D

E. C and D

Why might a solvent like turpentine be better for removing grease and grime than water? a. Like dissolves like b. oil and grease have similar interatomic forces as the turpentine and so are more soluble c. water is too polar and doesn't interact well with the non polar oils d. oil and grease have very limited solubility in the water e. all of the above

E. all of the above

Which of the following is the weakest form of interatomic attraction... a. a chemical bond b. an ion-dipole interaction c. a dipole-dipole interaction d. a dipole-induced dipole interaction e. an induced dipole-induced dipole interaction

E. an induced dipole-induced dipole interaction

How is the solubility of a solid affected by temperature? a. as the temperature goes up, the solubility goes up b. as the temperature goes down, the solubility goes down c. as the temperature goes up, the solubility goes down d. as the temperature goes down, the solubility goes up e. both A and B

E. both A and B

Which of the following solutions is the most dilute? a. 0.1 liter of water with 1 gram of sugar b. 0.2 liter of water with 2 grams of sugar c. 0.5 liter of water with 5 grams of sugar d. 1 liter of water with 10 grams of sugar e. they all have the same concentration

E. they all have the same concentration

Which of the following intermolecular forces best described why molecules like sucrose are very water soluable? a. dipole-dipole b. induced dipole-induced dipole c. dipole-induced dipole d. ion-dipole e. hydrogen bonding

E. hydrogen bonding

Would you expect to find more dissolved oxygen in polar or tropical ocean water? why?

there would be more dissolved oxygen in the POLAR oceans because the solubility of oxygen in water decreased with increasing temperature