Chem 1010 Ch 7

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

If you need 3.01 × 1023 molecules of sucrose, how many liters of a 4.00 molar solution would you need? 0.125 L 0.250 L 4.00 L 1.00 L

0.125 L

Which of the following solutions is the most concentrated? 0.5 L of a 3 molar solution 3.0 L of a 0.5 molar solution 2.0 L of a 1 molar solution 0.5 L of a 1 molar solution 2.0 L of a 2 molar solution

0.5 L of a 3 molar solution

Which of the following solutions is the most concentrated? 0.1 liter of water with 1 gram of sugar 2 liters of water with 0.2 gram of sugar 0.5 liter of water with 50 grams of sugar 3 liters of water with 30 grams of sugar They all have the same concentration.

0.5 liter of water with 50 grams of sugar

How many moles of sugar, C12H22O11, are there in 200. grams? 1.00 moles 68,400 moles 0.585 moles 0.684 moles

0.585 moles

What is the molarity of 0.50 liters of a solution with five moles of sucrose in it? 10. molar 0.5 molar 5 molar 2.5 molar

10. molar

If you need 10. moles of sucrose, how many liters of a 4.0 molar solution would you need? 2.5 L 0.25 L 25 L 10. L

2.5 L

How many grams of sugar (sucrose) are there in 5.0 liters of sugar water that has a concentration of 0.50 grams per liter of solution? 50 g 25 g 2.5 g 1.5 g

2.5 g

If the solubility of a compound is 30 grams per liter, how much solid is left undissolved if you mix 30 g of the compound in 0.33 L of solution? 5 g 10 g 20 g 30 g

20 g

A solid has a solubility at room temperature of 78 grams per liter. If 1.0 L of a heated solution containing 100. g of solute is cooled to room temperature, how much solid is formed? 100 g 22 g 78 g 1 L

22 g

How many molecules of sucrose are in 0.500 L of a 1.00 molar solution of sucrose? 3.01 × 1023 molecules of sucrose 6.02 × 1023 molecules of sucrose 12.04 × 1023 molecules of sucrose 0.5

3.01 × 1023 molecules of sucrose

How many molecules of sucrose are in a 0.500 moles of sucrose? 3.01 × 1023 molecules of sucrose 6.02 × 1023 molecules of sucrose 12.04 × 1023 molecules of sucrose Impossible to tell

3.01 × 1023 molecules of sucrose

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? 36 g 72 g 144 g 30 g

36 g

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

4 M

How many grams of sodium chloride are needed to make 15 L of a solution that has a concentration of 3.0 g per liter of solution? 30. g 141 g 5.0 g 45 g

45 g

How many moles of water are there in 100. grams of water? 1800 moles 100 moles 0.018 moles 5.55 moles

5.55 moles

How many molecules of sucrose are in 0.5 00L of a 2.00 molar solution of sucrose? 3.01 × 1023 molecules of sucrose 6.02 × 1023 molecules of sucrose 12.04 × 1023 molecules of sucrose 1 gram

6.02 × 1023 molecules of sucrose

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

Add more sugar. If it does not dissolve after mixing, the solution is saturated.

Which has the most atoms? a mole of gold a mole of helium a mole of lead All have the same number of atoms.

All have the same number of atoms.

How is the solubility of a gas affected by temperature? It depends on the gas As temperature goes down, the solubility goes down. As temperature goes up, the solubility goes up. As temperature goes down, the solubility goes up.

As temperature goes down, the solubility goes up.

Account for the observation that ethyl alcohol, C2H5OH, dissolves readily in water but dimethyl ether, C2H6O, which has the same number and kinds of atoms, does not. The hydrogens on the dimethyl ether surround the molecule, shielding the inner atoms from interacting with the water. Because the carbons arrange themselves in a straight line, the ethanol can interact more easily with more water molecules, thus increasing its solubility. 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. Because dimethyl ether lacks an -OH group, it is significantly less polar than is ethyl alcohol and is not readily soluble in water.

Because dimethyl ether lacks an -OH group, it is significantly less polar than is ethyl alcohol and is not readily soluble in water.

What is the main difference between a dipole-dipole interaction and a dipole-induced dipole interaction? Both are similar, but one involves a temporary dipole created by a permanent dipole. Dipole-dipole interactions are weaker because the dipoles are permanent. Dipole-induced dipole interactions are stronger because the induced dipoles can be formed at any time. Both are identical.

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

Chlorine is a gas at room temperature, but bromine is a liquid. Explain. Chlorine atoms are larger and this makes the formation of induced dipole-induced dipole attractions more favorable. Bromine atoms are larger and this makes the formation of induced dipole-induced dipole attractions more favorable. The smaller chlorine molecules are able to pack together in a tighter physical orientation. The bromine ions are held together by ionic bonds.

Bromine atoms are larger and this makes the formation of induced dipole-induced dipole attractions more favorable.

Which of the following would have the highest boiling point? C6H14 C8H18 C10H22 C12H26

C12H26

Which of the following would have the weakest induced dipole-induced dipole interactions? C6H14 C8H18 C10H22 C12H26 not enough information given

C6H14

Which of the following would have the lowest melting point? CCl4 CBr4 CF4 CI4 not enough information given

CF4

Which of the following might have the lowest solubility in water? CH3OH Cl2 O2 CH3CH3 none of the above

CH3CH3

Which of the following molecules is most likely to show a dipole-dipole interaction? CH3OH CH3SH CH4 H-C-C-H A and B

CH3OH

Which of the following is most likely to have the weakest induced dipole-induced dipole interaction? Cl2 Br2 F2 I2 All of the above have the same interactions.

F2

Does a plastic bottle of fresh water sink or float in the ocean? Why? Sinks; The combined density of the plastic bottle plus the fresh water inside is greater than the density of the ocean water. Floats; The bottle filled with fresh water floats in ocean water because it is less dense than the ocean water. Floats then sinks; The bottle filled with fresh water floats in ocean water until the fresh water reaches the same temperature as the ocean water, at which point it sinks. Sinks slightly; The added density of the plastic bottle will cause the bottle to sink slightly. It would most likely sink less than a foot where the density of the ocean water would be equal to or greater than the bottle of fresh water.

Floats; The bottle filled with fresh water floats in ocean water because it is less dense than the ocean water.

Which of the following molecules would you expect to be the most strongly attracted to a Cl- ion? H-F H3C-CH3 Cl-Cl F-F CCl4

H-F

Which of the following molecules would you expect to be the least attracted to a Na+ ion? H-F H3C-CH3 Cl2CH2 F- HO-

H3C-CH3

Hydrogen chloride, HCl, is a gas at room temperature. Would you expect this material to be very soluble or not very soluble in water? HCl is very soluble in water by virtue of the dipole/dipole attractions occurring between the HCl and H2O molecules. It is not very soluble because it is a gas, and all gases have very low solubility in water at room temperature. HCl is very soluble in water because it is such a small molecule, there is little electrical attraction to other HCl molecules. 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.

HCl is very soluble in water by virtue of the dipole/dipole attractions occurring between the HCl and H2O molecules.

Which of the following would have the highest boiling point? Cl2 Br2 F2 I2 not enough information given

I2

An inventor claims to have developed a new perfume that lasts a long time because it doesn't evaporate. Comment on this claim. A perfume that does not evaporate could be toxic since the molecules never leave the skin. In order to smell something, the molecules must evaporate and reach your nose. If the new perfume doesn't evaporate, it will not have an odor. This would be impossible to make because the perfume would have to be pressurized in order to not evaporate. This product is sure to sweep the market making many happy customers.

In order to smell something, the molecules must evaporate and reach your nose. If the new perfume doesn't evaporate, it will not have an odor.

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

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

How is the solubility of a solid affected by temperature? As temperature goes up, the solubility goes up. As temperature goes down, the solubility goes down. As temperature goes up, the solubility goes down. As temperature goes down, the solubility goes up. It depends on the solid

It depends on the solid

What statement best describes a mole? a little furry mammal that lives in the ground a very small number chemists use to count atoms or molecules the amount of molecules or atoms in 1 gram of something It is a very large number chemists use to count atoms or molecules.

It is a very large number chemists use to count atoms or molecules.

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

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

Why do red blood cells, which contain an aqueous solution of dissolved ions and minerals, burst when placed in fresh water? The dissolved ions provide a pressure that eventually bursts open the cell. More water molecules enter the cell than leave the cell. The fresh water acts to dissolve the blood cell wall. all are correct

More water molecules enter the cell than leave the cell.

Red blood cells have a high concentration of dissolved ions. When placed into pure water they rupture. Why? Osmosis draws water into the cell until it pops. Water dissolves the cell membrane. Osmosis draws water out of the cell until it tears. The cells are not stable outside of a biological host.

Osmosis draws water into the cell until it pops.

Which of the following molecules is most likely to show a dipole-dipole interaction? SO2 CO2 CH4 H-C-C-H

SO2

A student is told to use 10.00 grams of sodium chloride to make an aqueous solution that has a concentration of 1.00 grams of sodium chloride per liter of solution. How much water will she use in making this solution? Much more than 10 L Exactly 10 L Slightly less than 10 L 1L

Slightly less than 10 L

How are intermolecular forces and solubility related? Solubility depends on the solvent's ability to overcome the intermolecular forces in a solid. Solubility depends on the solute's ability to overcome the intermolecular forces in the solvent. Solubility is a measure of how strong a solvent's intermolecular forces are. Solubility is a measure of how weak the intermolecular forces in the solute are.

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

Describe what usually happens to a hot solution that is saturated with a solid as it cools. The solid that is dissolved comes out of the solution completely. The solid stays in the solution. Some of the solid comes out of the solution. The solution freezes.

Some of the solid comes out of the solution.

Fish don't live very long in water that has just been boiled and brought back to room temperature. Suggest why. There is now a higher concentration of dissolved CO2 in the water. The nutrients in the water have been destroyed. Since some of the water was evaporated while boiling, the salts in the water are now more concentrated. This has a negative effect on the fish. The boiling process removes most of the air that was dissolved in the water. Upon cooling the water is void of its usual air content, hence, the fish drown.

The boiling process removes most of the air that was dissolved in the water. Upon cooling the water is void of its usual air content, hence, the fish drown.

If you were to increase the pressure of a gas above a liquid (such as by pressing a piston above a liquid) what happens? The gas is forced into solution and the solubility increases. The solution is compressed and the gas is forced out of the solvent. The pressure goes down and the gas moves out of the solvent. The pressure goes down and the gas goes into the solvent. The amount of gas in the solution would stay the same.

The gas is forced into solution and the solubility increases.

Why is the surface area of a gecko's foot so extensive? A gecko, like all amphibians, needs extensive surface area under foot for stability on land as well as mobility in water. A gecko's foot acts like a large dipole and thus allows for ion-dipole interaction in water. The greater the surface area the greater the number of induced dipole-induced dipole forces of attraction that can occur between the gecko's foot and the surface. The extensive surface area, once charged by the gecko's body, allows for the dipole-dipole attraction of every contact surface.

The greater the surface area the greater the number of induced dipole-induced dipole forces of attraction that can occur between the gecko's foot and the surface.

If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound? The ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution. The ionic bond is weakened by the ion-dipole interactions and ionic repulsion ejects the ions from the crystal. The ion-dipole interaction causes the ions to heat up and vibrate free of the crystal. The ions never overcome their interatomic attraction and therefore are not soluble.

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

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

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

Which of the following accurately describes osmosis? The more concentrated solution absorbs water from the less concentrated solution. The less concentrated solution absorbs water from the more concentrated solution. The less concentrated solution gets more dilute. The ions migrate from the more concentrated solution to the less concentrated.

The more concentrated solution absorbs water from the less concentrated solution.

What happens if you were to place a dilute solution that is in a bag made of a semipermeable membrane and were to then suspend it in a very concentrated solution? The size of the suspended bag would decrease. The size of the suspended bag would increase. The size of the bag would not change. The solutions would eventually reach the same concentration.

The size of the suspended bag would decrease.

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? The size of the suspended bag would decrease. The size of the suspended bag would increase. The size of the bag would not change. The solutions would eventually reach the same concentration.

The size of the suspended bag would increase.

Would you expect to find more dissolved oxygen in polar or tropical ocean waters? Why? There would be more dissolved oxygen in the tropical oceans because intense tropical storms mix up the atmospheric oxygen into the ocean water. There would be more dissolved oxygen in the polar oceans because the colder oxygen would "sink" and dissolve into the water. There would be more dissolved oxygen in the tropical oceans because the heated oxygen molecules in the air would collide with and mix into the water. There would be more dissolved oxygen in the polar oceans because the solubility of oxygen in water decreases with increasing temperature.

There would be more dissolved oxygen in the polar oceans because the solubility of oxygen in water decreases with increasing temperature.

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. These are dissolved salts heating up and escaping from the water. These bubbles are formed as the surrounding gases from the air dissolve into the water as it is heated. They are very minute pockets of water in the gaseous phase. When they get large enough, the water will boil as this gas escapes. 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.

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.

Which of the following solutions is the most dilute? 0.1 liter of water with 1 gram of sugar 0.2 liter of water with 2 grams of sugar 0.5 liter of water with 5 grams of sugar 1 liter of water with 10 grams of sugar They all have the same concentration.

They all have the same concentration.

A saturated solution of compound X in water has a greater concentration than does a saturated solution of compound Y. Does it follow that compound X is also more soluble in water? No, the greater the concentration of a compound in water, the less soluble it is. Yes, compound X is more soluble than is compound Y because a greater concentration in water can be obtained. No, concentration of a solution is not correlated with how soluble that solution is in water. Since both solutions are saturated, it cannot be determined which compound has a greater solubility.

Yes, compound X is more soluble than is compound Y because a greater concentration in water can be obtained.

Treating water with chlorine or ozone during water purification is an example of ________. a physical change a chemical reaction ion exchange a solid dissolving in a liquid

a chemical reaction

Which of the following describes an aqueous solution? a mixture of some compound dissolved in water a mixture of polar molecules dissolved in a nonpolar solvent a mixture of water dispersed in an ionic compound a mixture of nonpolar molecules dissolved in a polar solvent

a mixture of some compound dissolved in water

A soap molecule is ________. primarily polar primarily nonpolar a molecular with both a polar and nonpolar part a neutral compound

a molecular with both a polar and nonpolar part

What is a hydrogen bond? a special type of dipole-dipole attraction involving hydrogen bound to a highly electronegative atom a special type of dipole-dipole attraction involving hydrogen bound to any other atom a special type of dipole-dipole attraction involving hydrogen bound to another hydrogen atom a special type of attraction involving any molecules that contain hydrogens

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

A 1 molar solution of sucrose (Formula Weight 342.6 g/mol) solution contains ________. 1 mole of sucrose 342.6 g of sucrose 6.02\:\times10^{23} molecules of sucrose all are correct

all are correct

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

all of the above

In which of the following molecules will water induce a temporary dipole? CO2 O2 N2 all of them none of them

all of them

Which of the following is the weakest form of interatomic attraction? a chemical bond an ion-dipole interaction a dipole-dipole interaction a dipole-induced dipole interaction an induced dipole-induced dipole interaction

an induced dipole-induced dipole interaction

Of the following, which is the strongest form of intermolecular attraction? a chemical bond an ion-dipole interaction a dipole-dipole interaction a dipole-induced dipole interaction an induced dipole-induced dipole interaction

an ion-dipole interaction

Hard water contains excessive amounts of ________. chlorine ions calcium ions hydrogen ions hydroxide ions

calcium ions

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

dipole

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

he water molecule aligns such that the oxygen interacts with the sodium.

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

iron

Under which of the following conditions would you expect the highest solubility of oxygen gas in water? high temperature and low pressure above the solution low temperature and high pressure above the solution low temperature and low pressure above the solution high temperature and high pressure above the solution

low temperature and high pressure above the solution

In a solution of 77 percent nitrogen and 23 percent oxygen, which is the solvent? oxygen nitrogen both neither Gases cannot form solutions.

nitrogen

What is the difference between a dipole-dipole interaction and an ion-dipole interaction? one involves hydrogen bonding while the other does not one involves salts and water while the other doesn't involve water one involves ionic molecules interacting with other ionic molecules while the other deals with polar molecules one involves dipole attraction between molecules while the other involves dipole interactions between molecules and ions

one involves dipole attraction between molecules while the other involves dipole interactions between molecules and ions

Which of the following solutions is the most dilute? one liter of water with 1 gram of sugar one liter of water with 2 grams of sugar one liter of water with 5 grams of sugar one liter of water with 10 grams of sugar

one liter of water with 1 gram of sugar

Which of the following solutions is the most concentrated? one liter of water with 1 gram of sugar one liter of water with 2 grams of sugar one liter of water with 5 grams of sugar one liter of water with 10 grams of sugar

one liter of water with 10 grams of sugar

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

separation of charges

Fluorine is a relatively ________. large atom soft atom small atom greenish atom

small atom

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

sugar

What property primarily determines the effect of temperature on the solubility of gas molecules? the kinetic energy of the gas the polarity of the gas the molecular weight of the gas the ionic strength of the gas

the kinetic energy of the gas

What is molarity? the number of grams of solute per liter of solution the number of moles of solute per liter of solvent the number of liters of solute per mole of solution the number of moles of solute per liter of solution

the number of moles of solute per liter of solution

During osmosis ________. the water moves into the concentrated solution faster than it leaves the ions move into the concentrated solution faster than they leave the water moves more slowly into the concentrated solution than it leaves the ions move into the concentrated solution slower than they leave

the water moves into the concentrated solution faster than it leaves