CHM 112 chapter 13
Which of the following intermolecular forces help to stabilize a DNA double helix? Select all that apply.
-Ion-dipole forces -Hydrogen bonds -Dispersion forces
______ alcohols are more soluble in water and ______ alcohols are more soluble in nonpolar solvents like hexane.
Smaller; larger
Coupled complementary bases on each side of the double helix chain
connect via H bonds.
A solution usually has a _____ entropy than either the pure solvent or pure solute because in the solution there are a _____ number of interactions between particles and therefore _____ ways to distribute the energy of the system.
higher; greater; more
A solution containing a nonvolatile solute always boils at a _____ temperature than the pure solvent. The vapor pressure of the solution is _____ than the vapor pressure of the pure solvent; hence the solution must be heated to a _____ temperature in order for the vapor pressure to equal the external pressure.
higher; lower; higher
Stacked N-containing bases
interact via dispersion forces.
Phospholipids self-assemble in water into a lipid bilayer because of ______ intermolecular attractive forces between the polar heads and water and ______ intermolecular attractive forces between the nonpolar tails within the bilayer interior.
ion-dipole; dispersion
Henry's law states that the solubility of a ______ in a solvent is directly proportional to the ______.
gas; pressure of that gas above the solution
When an ionic compound is dissolved in water, the overall enthalpy change ΔHsoln is the combination of the _____ energy, which is the energy required to separate the ions, and the heat of _____ of the ions.
lattice; hydration
A solute that is nonvolatile is one that has a relatively _____ vapor pressure at the boiling point of the solvent.
low
Colligative properties are properties of a solution that depend only on the _____ of solute particles in a given volume of solution, not on their _____.
number; type
Which of the following options give the correct formula to calculate the concentration of a solution in ppm and ppb by mass? Select all that apply.
ppb = mass of solutemass of solutionmass of solutemass of solution x 109 ppm = mass of solutemass of solutionmass of solutemass of solution x 106
Down a group
ΔHhydr decreases as charge densities decrease.
Place the following aqueous solutions in increasing order (lowest at the top of the list) of osmotic pressure, assuming ideal behavior. Instructions
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For very dilute solutions, two terms are often used to express concentration (type the abbreviation): mass of solutemass of solution x 109 = mass of solutemass of solution x 106 =
Blank 1: ppb Blank 2: ppm
Which of the following statements correctly describe the components of the aqueous heats of solution, ΔHsoln? Select all that apply.
-ΔHsoln = ΔHlattice + ΔHhydr of the ions -ΔHlattice is always a positive value.
Which of the following statements correctly describe the heat of solvation, ΔHsolvation, and heat of hydration, ΔHhydr, for a solution process? Select all that apply
-ΔHsoln = ΔHsolute + ΔHsolvation -ΔHsolvation = ΔHsolvent + ΔHmix
A solution is made by dissolving 67.7 g of urea (CH4N2O; molar mass = 60.06 g/mol) in 833 g of CHCl3 (molar mass = 119.36 g/mol). Order the following steps correctly to calculate the boiling point of the solution if Kb for CHCl3 = 3.85°C⋅kg/mol and the normal boiling point for this solvent is 61.2°C. Place the first step at the top. Instructions
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Gases with stronger intermolecular forces are generally ______ soluble than gases with weaker intermolecular forces in a polar liquid like water. A gas that reacts with a solvent will appear to have a ______ solubility.
more; high
The most abundant component of a solution is usually called the________, , whereas the other dissolved components are called _________.
solvent, solute
Which of the following are applications of freezing point depression? Select all that apply.
-Biological antifreeze -Refining petroleum -"Salting" frozen roads -Car antifreeze
HCl C6H12O6 MgCl2
- i = 2 - i = 1 - i = 3
Concentrated aqueous HCl contains 38% w/w HCl. Calculate the mass of water present in 250. g of this solution.
155 g H2O
Suspension Solution Colloid
- A heterogeneous mixture containing particles large enough to be seen by the naked eye; particles will settle out on standing - A homogeneous mixture where the particles are too small to be visible; particles are distributed evenly in the solvent - A dispersion of particles in a dispersing medium; particles are too small to settle out but large enough to scatter light
Which of the following statements correctly describe different types of mixtures? Select all that apply.
- A heterogeneous mixture contains two or more different phases. -The composition of any mixture is variable. -Differences in particle size account for the main differences between solutions and colloids.
Psolvent Xsolvent P°solvent
- Vapor pressure of the solvent in the solution - Mole fraction of the solvent in the solution -Vapor pressure of the pure solventVapor
Ion-dipole
NaCl in CH3CH2OH
Calculate the mole fraction of KBr (molar mass 119.00 g/mol) in a solution made by dissolving 0.30 g KBr in 0.400 L of H2O (d = 1.00 g/mL; molar mass 18.02 g/mol).
1.14 × 10-4
A solution is prepared by mixing 10.5 g of NaCl (molar mass 58.44 g/mol) with 147 g of H2O (molar mass 18.02 g/mol). The final volume of the solution is 150. mL. Which of the following options are the correct values for molarity (M) and molality (m) of the solution? Select all that apply.
1.20 M 1.22 m
A solution of 1.90 g of a nonelectrolyte in 500.0 mL of water at 27.0°C has an osmotic pressure of 39.5 mmHg. What is the molar mass of the compound?
1.71 × 103 g/mol
Dipole-induced dipole forces
A nonpolar solute in a polar solvent
Ion-induced dipole forces
A nonpolar solute in a polar solvent that also contains dissolved ions
Concentrated
A relatively large amount of solute dissolved in a given quantity of solvent
Dilute
A relatively small amount of solute dissolved in a given quantity of solvent
Ion-dipole forces
An ionic solute in a polar solvent
B - nonploar tail
Fatty acid chains or nonpolar tail
Helical and sheetlike segments
H bonds between C=O of one peptide bond and the H-N of another
Dispersion forces
I2 in hexane (C6H14)
Protruding side chains into the surrounding cell fluid
Ion-dipole forces and H bonds
Which step(s), involved in the formation of a solution, is/are associated with a positive sign for ΔH? Select all that apply.
Solvent particles separate from each other. Solute particles separate from each other.
What does the term "like dissolves like" mean?
Substances that have similar types of intermolecular forces dissolve in each other.
How does the presence of a strong electrolyte in solution affect the colligative properties of a solution when compared to the same number of moles of a nonelectrolyte solute?
The electrolyte dissociates or ionizes to give a larger number of moles of dissolved particles, with a greater effect on the colligative properties.
Solubility
The maximum amount of a solute that can dissolve in a fixed quantity of a particular solvent at a given temperature
What is the solubility of potassium chlorate in aqueous solution at room temperature, 25oC, with reference to the graph of solubility vs. temperature provided?
The maximum amount of potassium chlorate that will dissolve in 100 g H2O at 25oC is about 8 g.
True or false: All gases are miscible with each other.
True
A saturated solution of a gas in a liquid (in a closed system) is at equilibrium with a fixed number of gas molecules leaving and entering the solution every second. If the pressure on the system is increased, the gas volume will _____, thus disturbing the system. This causes _____ gas molecules to dissolve in order to reestablish equilibrium. A gas is therefore _____ soluble at higher pressures.
decrease; more; more
The magnitude of the heat of hydration of an ion _____ down a group on the periodic table and _____ from left to right across a period. (The term magnitude indicates the value of the heat of hydration, not its sign.)
decreases; increases
Freezing point _____ is observed for solutions containing nonvolatile solutes. The vapor pressure of a solution is _____ than that of the pure solvent, and the solution therefore freezes at a _____ temperature.
depression, lower, lower
A solution containing 1 mol of a strong electrolyte will have a(n) _____ effect on the colligative properties of the solution than 1 mol of a nonelectrolyte. A strong electrolyte will dissociate or ionize in aqueous solution, and therefore the total number of dissolved solute particles is _____ for 1 mol of a strong electrolyte than for 1 mol of a nonelectrolyte solute.
greater; greater
Most strong electrolyte solutions are not ideal so that the measured value of the van't Hoff factor i is _____ than expected from the formula of the compound. This is because ions in solution are not totally isolated from each other, but remain clustered together to form an ionic atmosphere. This _____ the effective concentration of particles and therefore the measured value of i.
lower; decreases
Solubility is defined as the______amount of solute that is able to dissolve in a fixed amount of a particular solvent at a particular_____and pressure..
maximum, temperature
Most solids are _____ soluble in a particular solvent at higher temperatures than at lower temperatures, although there are some exceptions. The solubility of a gas in water will generally _____ as temperature increases.
more; decrease
In an ideal solution of a strong electrolyte, the van't Hoff factor i is equal to _____.
the number of moles of particles produced by dissociation of 1 mol of the electrolyte
Saturated
a solution containing the maximum amount of dissolved solute; more solute added will not dissolve
Unsaturated
a solution that contains less than the equilibrium concentration of dissolved solute; more solute added will dissolve
Aerosol Emulsion Sol Foam
- Liquid or solid dispersed in a gas - One liquid dispersed in another - Solid dispersed in a liquid - Gas dispersed in a liquid
Isotonic solution Hypotonic solution Hypertonic solution
- The cell maintains its normal shape as water enters and leaves at the same rate. - The cell expands as water enters at a greater rate than it leaves. - The cell contracts as water leaves at a greater rate than it enters.
Strong electrolyte Weak electrolyte Nonelectrolyte
- shows 100% dissociation in aqueous solution; ions are produced and the solution conducts electricity well - low % dissociation in aqueous solution; a few ions are produced and the solution conducts poorly - does not dissociate at all in aqueous solution; no ions are produced and the solution does not conduct an electric current
Calculate the freezing point of a solution containing 0.204 mol of ibuprofen in 250. g of ethanol. (Kf for ethanol = 1.99oC⋅kg/mol and Tf = -117.3oC.)
-118.9oC Reason: ΔTf = 0.2040.250 × 1.99 = 1.62oC and Tf = -117.3oC - 1.62oC = -118.9oC
ΔTb = m = Moles of benzoic acid present = Mass of benzoic acid =
-82.5°C - 78.1°C -4.4°C1.20°C⋅kg/mol -78.1 g ethanol × 1kg1000g × 3.7mol benzoic acid1kg ethanol -0.29 mol × 122.12g1mol
Which of the following statements correctly describe gas-liquid solutions? Select all that apply.
-A polar gas will dissolve readily in a polar solvent. -A nonpolar gas will not dissolve readily in a polar solvent. -Gases appear to be more soluble in aqueous solution if they react with H2O after dissolving.
Both soaps and cell membranes rely on the behavior of molecules with dual polarity. Which of the following statements correctly describe this behavior? Select all that apply.
-A soap functions because the nonpolar "tails" of the molecules bond to grease and the polar "heads" carry the grease into the solvent. -The lipid molecules that make up a cell membrane have a nonpolar hydrocarbon portion and a polar-ionic "head." -A cell membrane maximizes contact between parts of the lipid molecules that have the most similar types of intermolecular forces.
Which of the following colloids are correctly classified? Select all that apply.
-A sol is a solid dispersed in a liquid. -An aerosol is a solid dispersed in a gas. -An aerosol is a liquid dispersed in a gas.
What are the features of a nonvolatile, nonelectrolyte solute? Select all that apply.
-A solute that dissolves but produces no ions in solution -A solute that has a negligible vapor pressure at the boiling point of the solvent
Which of the following statements correctly describe the behavior of KNO3 in aqueous solution, with reference to the graph of solubility vs. temperature provided? Select all that apply.
-A solution containing 40 g of KNO3 in 100 g H2O at 30°C will become unsaturated when it is heated to 35°C. -The maximum amount of KNO3 that will dissolve in 100 g H2O at 30°C is about 42 g. -If a solution containing 65 g of KNO3 in 100 g of H2O at 70°C is cooled slowly, crystals will begin to appear at around 42°C.
Which of the following are applications of osmotic pressure? Select all that apply.
-Absorption of water in trees -Regulation of bodily water volume -Safe delivery of nutrients or drugs intravenously -Food preservation
Certain substances such as alcohols are able to dissolve fairly readily in both polar and nonpolar solvents. Which statements correctly explain this behavior? Select all that apply.
-Alcohols form strong interactions with both types of solvent. -The hydrocarbon portion of the alcohol interacts with the nonpolar solvent through dispersion forces. -Alcohols have dual polarity since they possess a polar OH group as well as a nonpolar hydrocarbon portion.
Which of the following options correctly describes the effect of temperature on the solubility of a gas in a given solvent?
-An increase in temperature generally causes a decrease in the solubility of a gas. -An increase in temperature increases the energy of the gas particles, allowing them to escape the solvent more easily.
Which of the following statements correctly relate the charge density of an ion to heat of hydration? Select all that apply.
-As the charge on an ion increases and its radius decreases, its charge density will increase and so will the magnitude of the heat of hydration. -An ion with a higher charge density has a more negative heat of hydration than an ion of similar size but lower charge.
Which of the following compounds are expected to be soluble in carbon tetrachloride (CCl4) based on structure? Select all that apply.
-CO2 -C6H6
Molarity to molality Mole fraction to molality Mass percent to molarity
-Density of the solution -Molar masses -Molar masses and density of the solution
Which of the following is an intermolecular force exhibited in a solution of CH3OCH3 in CH3OH? Select all that apply.
-Dipole-dipole forces -Dispersion forces -Hydrogen bonding
Which of the following statements correctly describe entropy? Select all that apply.
-Entropy is related to the number of ways a system can disperse its energy. -Entropy is related to the freedom of motion of the particles in a system. -The entropy of a gas is higher than the entropy of a liquid.
Which of the following statements correctly describe the change in entropy when a solution is formed? Select all that apply.
-Entropy usually increases when a solution forms because there are more interactions between particles in a solution. -The particles in a solution generally have a greater freedom of movement than the particles in a pure solute.
Which of the following statements correctly describe the molality and molarity of a solution? Select all that apply.
-For a dilute aqueous solution molality and molarity are nearly equal. -M must be calculated using the volume of the solution, not the volume of the solvent. -Both molarity and molality express concentration in terms of moles of solute.
Which of the following statements correctly describe solutions consisting of gases and/or solids? Select all that apply.
-Gas-gas solutions form readily because all gases are miscible with each other. -A gas may dissolve in a solid by occupying the spaces between the solid particles. -Gas-solid solutions are important as catalysts.
Which of the following statements correctly describe the heat of solvation for a solution process? Select all that apply.
-If ΔHhydr < 0, then more energy is released due to solvent-solute attraction than the energy absorbed in separating solvent particles. -The heat of solvation is called the heat of hydration if H2O is the solvent. -The heat of solvation is the enthalpy change that occurs when a solute particle is surrounded by solvent particles.
Which of the following options correctly describe the effect of temperature on the solubility of a solid in a given solvent? Select all that apply.
-In general, solids are more soluble at higher temperatures than at lower temperatures. -There is no clear correlation between ΔHsoln and solubility at different temperatures.
Which of the following statements correctly describe the behavior of different types of substances in aqueous solution? Select all that apply.
-Nonelectrolytes do not produce ions in solution. -MgCl2 is a strong electrolyte and 1 mol of MgCl2 will produce 3 moles of ions in aqueous solution. -CH3COOH is a weak electrolyte, and when this substance is dissolved in H2O, there will be a mixture of CH3COOH molecules, CH3COO- ions, and H3O+ ions.
Which of the following statements correctly describe the osmotic pressure (Π) of a solution? Select all that apply.
-Osmotic pressure is directly proportional to the molarity of the solution. -Osmotic pressure increases with temperature.
A solution contains 0.32 mol naphthalene in 5.50 mol of toluene at 32oC. Pure toluene has a vapor pressure of 41 torr at this temperature. Which of the following options correctly solve for both P and ΔP for this solution? Select all that apply.
-P = 5.500.32+5.505.500.32+5.50 x 41 = 39 torr -ΔP = 0.320.32+5.500.320.32+5.50 x 41 = 2.3 torr
Which of the following options correctly show the relationships between solute concentration and solution vapor pressure? Select all that apply.
-Psolvent = Xsolvent x P°solvent -ΔP = Xsolute x P°solvent
Which of the following options that correctly describe Henry's law for gases? Select all that apply. Sgas = kH x Pgas
-Sgas is the solubility of the gas at a particular temperature. -Pgas is the partial pressure of the gas above the liquid. -This law shows that the solubility of a gas increases with pressure.
Which of the following statements correctly describe the effect of alcohol structure on solubility? Select all that apply.
-Smaller alcohols are more soluble in H2O than larger alcohols. -As the hydrocarbon chain increases in length, the alcohol becomes less soluble in polar solvents.
Which of the following statements correctly explain the effect of a nonvolatile solute on the vapor pressure of a solution? Select all that apply.
-Solute particles on the solution surface decrease the number of solvent particles that can escape. Vapor pressure is lowered. -The entropy of the solution is higher than that of the pure solvent. Solvent has less tendency to vaporize, and the vapor pressure is lowered.
Which of the following options describe situations in which hydrogen bonding will be observed between the solute and the solvent? Select all that apply.
-Solvent and solute both contain OH or NH groups. -Solvent contains OH or NH groups, solute contains N, O, or F atoms. -Solvent contains N, O, or F; solute contains OH or NH groups.
Which of the following options correctly describe a solution that is in contact with undissolved solute at a given temperature? Select all that apply.
-The concentration of dissolved solute will not change. -Undissolved solute is in equilibrium with dissolved solute. -The rate at which solute is dissolving is equal to the rate at which solute particles are crystallizing from solution.
Will HCl (g) or NaCl (s) be more soluble in the solvent CH3OCH3? Why?
-The dipole-dipole forces in an HCl solution are similar in strength to the dipole-dipole forces between CH3OCH3 molecules. -HCl (g) will be more soluble in CH3OCH3.
Which of the following statements correctly describe the vapor pressure of a solution containing a volatile nonelectrolyte solute? Select all that apply.
-The fraction of the volatile component in the vapor will be greater than that in the solution. -The vapor pressures of both volatile components will be lowered. -The vapor pressure of each volatile component can still be calculated using PA = XAPoA.
Which of the following statements correctly describe freezing point depression for a solution? Select all that apply.
-The freezing point constant Kf is characteristic of the solvent. -ΔTf is a positive value. -Freezing point depression is proportional to the molality of the solution.
Which of the following options correctly reflect the effect of a nonvolatile solute on the boiling point of a solution? Select all that apply.
-The greater the concentration of the solute, the higher the boiling point will be. -Boiling point elevation occurs because the presence of a nonvolatile solute lowers the vapor pressure of the solvent. -The lower the concentration of the nonvolatile solute, the higher the vapor pressure of the solution. -A solution boils at a higher temperature than the pure solvent.
Which of the following statements correctly describe the relationship between enthalpy and entropy changes in the formation of a solution? Select all that apply.
-The most favorable solution process involves an increase in entropy and a decrease in enthalpy. -If the solution process is endothermic, a solution will still be able to form if ΔS is large.
Which of the following statements correctly describe the enthalpy changes associated with the formation of a solution? Select all that apply.
-The overall enthalpy change for the solution process depends on the balance of energy absorbed vs. energy released. -Energy is released when the solvent and solute particles attract each other and mix to form a solution. -Energy is absorbed to separate the solvent particles from each other.
Which of the following statements correctly describe the behavior of solutions, suspensions, and colloids? Select all that apply.
-The particles in a solution are evenly distributed in the solvent. -The major factor that causes suspension, solutions, and colloids to differ is particle size. -The particles in a colloid are smaller than those in a suspension.
Which of the following statements correctly describes the action of Gramicidin A and similar antibiotics? Select all that apply.
-The polar interiors of these antibiotics pass along ions using ion-dipole forces. -Vast numbers of ions pass through the antibiotic per second. -These antibiotics form channels in the cell membrane of the bacterium.
Which of the following statements correctly describe solubility? Select all that apply.
-The solubility of a given substance in a particular solvent varies with temperature. -A concentrated solution contains a relatively large amount of solute in a given amount of solvent.
Which of the following options correctly describe the different ways of expressing the concentration of a solution? Select all that apply.
-The unit for molality (symbol m) is mol/kg. -To calculate mole fraction for a given mass of a reactant or product, the masses of all solution components must be known.
Which of the following statements correctly describe the structure and behavior of colloids? Select all that apply.
-There are different types of colloids, classified by the physical state of their components. -Colloid particles will coagulate and settle from the dispersion if the colloid is heated. -A colloid in H2O is stabilized by ion-dipole forces between the charged surfaces of the colloid particles and the H2O molecules.
A solution contains 44.0 mL of benzene (C6H6; d = 0.877 g/mL) in 125 mL of hexane (C6H14; d = 0.660 g/mL). Select all the options that correctly show the calculations needed to calculate both the mass % and the volume % of the solution.
-mass of hexane = 82.5 g -mass % = 38.6g121.2g38.6g121.2g × 100 = 31.8% w/w -The molecular formulas and molar masses of the compounds are not required for this calculation.
Molarity (M) Molality (m) Parts by mass Mole fraction (X)
-mol of soluteL of solution -mol of solutekg of solvent -mass of solutemass of solution -mol of solutetotal no. of moles present
A solution containing 0.64 g of adrenaline in 36.0 g of CCl4 has a boiling point of 76.99°C (Kb for CCl4 = 5.03°C/m and its normal boiling point is 76.50°C). Place the following steps in the correct order to calculate the molar mass of adrenaline, starting with the first step at the top of the list. Instructions
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Click and drag on elements in order A solution of glycerol (C3H8O3; molar mass = 92.09 g/mol) in ethanol (C2H5OH; molar mass = 46.07 g/mol) has a molality of 2.45 mol/kg. Correctly order the steps required to calculate the mole fraction of glycerol in this solution.
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What mass of pyrazole (C3H4N2; molar mass = 68.08 g/mol) must be added to 451 g of benzene (C6H6; molar mass = 78.11 g/mol) in order for the solution to have a freezing point of 0.5oC? (Kf for benzene = 5.12oC ⋅ kg/mol and the normal freezing point for this solvent is 5.5oC). Order the steps required to solve this problem correctly. Start with the first step at the top of the list. Instructions
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Calculate the osmotic pressure of a solution containing 3.55 g of sucrose (C12H22O11; molar mass 342.3 g/mol) in sufficient water to give 825 mL of solution at 22oC.
0.0126 × 0.0821 × 295 = 0.305 atm
What is the solubility of argon in water at 25∘C25∘C if the partial pressure of argon in air is 0.00916 atm? Henry's law constant for argon is1.61 mol/L·atm1.61 mol/L·atm.
0.0147 mol/L
A solution of volume 150. mL contains 0.015 g of Pb2+ ions. Calculate the concentration of Pb2+ in ppm if the density of the solution is 1.02 g/mL.
0.015g153g/0.015g153g x 106 = 98.0 ppm
Calculate the mass of O2 that will dissolve in 2.50 L of H2O that is in contact with air at 20oC, where the partial pressure of O2 is 0.209 atm. (kH for O2 in H2O at 20oC = 1.28 × 10-3 mol/L.atm.)
0.0214 g O2
A 0.50% by mass solution of KCl (molar mass 74.55 g/mol) in H2O (Kf = 1.86oC/m) has a freezing point of -0.234oC. What is the van't Hoff factor i for this solution?
1.87 Reason: The molality is 6.71×10−3mol0.0995kg6.71×10-3mol0.0995kg = 0.0674 m since there are 0.50 g in 99.50 g of H2O, not 0.50 g in 100.00 g of H2O. i = ΔTfKfmΔTfKfm = 0.234°C1.86°C/m×0.0674m0.234°C1.86°C/m×0.0674m = 1.87
Calculate the expected boiling point of a solution containing 0.72 mol of MgCl2 in 1.00 kg of H2O if Kb = 0.512°C⋅kg/mol.
100.0°C + (2.16 × 0.512) = 101.1oC Reason: MgCl2 dissociates to form three ions, so i = 3 and the molality is 2.16 mol/kg.
A solution contains 25.0 g ethanol (C2H5OH; molar mass 46.07 g/mol) in 500. g H2O (molar mass 18.02 g/mol) at 23oC. If the vapor pressure of pure H2O at this temperature is 20.57 torr, What is the vapor pressure of the solution?
20.1 torr Reason: Psoln = χsolvent x P°solvent. Since H2O is the solvent, we use χwater for this calculation. χwater = 27.728.3 = 0.979 Psoln = 0.979 x 20.57 = 20.1 torr
A 0.100 m solution of K2SO4 in H2O (Kf = 1.86°C/m) has a freezing point of -0.432°C. What is ideal value of the van't Hoff factor i and the actual experimentally determined value for K2SO4 in this solution?
3; 2.32
What mass of CCl4 is required to prepare a 0.25 m solution using 115 g of hexane? (Molar mass of CCl4 = 153.81 g/mol and molar mass of hexane = 86.17 g/mol.)
4.42 g
A solution of glucose (C6H12O6; molar mass = 180.16 g/mol) in water has an osmotic pressure of 2.68 atm at 35°C. What is the mass of glucose in 325 mL of solution?
6.21 g Reason: M = 2.68atm0.0821L⋅atm/mol⋅K×308K2.68atm0.0821L⋅atm/mol⋅K×308K = 0.106 M 325 mL × 1L1000mL1L1000mL × 0.106mol1L0.106mol1L = 0.0345 mol 0.0345 mol × 180.16g1mol180.16g1mol = 6.21 g glucose
A person is considered legally intoxicated in most states with a blood alcohol level of 80.0 mg/dL. Calculate this concentration in ppm if the density of blood plasma is 1.023 g/mL.
782 ppm
Which of the following options correctly describes the effect of temperature on the solubility of a gas in a given solvent?
An increase in temperature increases the energy of the gas particles, allowing them to escape the solvent more easily.
The compound Ca(NO3)2 dissociates in water to form____ mol of ions for every 1 mol of solute and its van't Hoff factor i is expected to be_____ in an ideal solution. The compound urea (CH4N2O) has an expected i value of____
Blank 1: 3 or three Blank 2: 3 or three Blank 3: 1 or one
A protein is a macromolecular polymer consisting of______ acids covalently bonded together. The_______ of the side chains of these components determine the intermolecular forces between different parts of the same protein molecule, thus influencing the overall_______ and function of a particular protein.
Blank 1: amino Blank 2: polarity, nonpolarity, structure, non-polarity, functional groups, bonding, interactions , or identity Blank 3: shape, structure, folding, or form
Gramicidin A and similar_____ function by forming a channel through the cell membrane. The______ groups along the outside of the channel interact with the membrane interior through______ forces, while the inside of the channel is lined with polar groups, which allow K+ and Na+ ions to pass through the cell via ion-dipole interactions.
Blank 1: antibiotics Blank 2: nonpolar, non polar, or hydrophobic Blank 3: dispersion or London
Light passes straight through a solution without scattering. By contrast light passed through a(n)_____ will scatter because the dispersed particles are similar in size to the wavelengths of visible light. This phenomenon is known as the_____ effect and is an important tool in distinguishing between the different types of mixtures.
Blank 1: colloid Blank 2: Tyndall
To convert a concentration unit based on mass to one based on volume, the_____ of the solution will be required.
Blank 1: density
When an ionic solute dissolves in water, the ions_____ and each ion becomes surrounded by a cluster of H2O molecules called a(n)______ shell.
Blank 1: dissociate, separate, or break apart Blank 2: hydration or solvation
The van't Hoff factor i is a measure of the effect of a solute on colligative properties. It is given by the ratio: measured value for_____ solution/expected value for______ solution. For any electrolyte i > 1 because an electrolyte_____ in solution.
Blank 1: electrolyte Blank 2: nonelectrolyte or non-electrolyte Blank 3: dissociates or ionizes
Both____ and entropy changes determine whether or not a given solvent-solute pair will form a solution. A solution process for which ΔHsoln > 0 will still be spontaneous if it is counterbalanced by a corresponding_____ in the entropy of the system.
Blank 1: enthalpy Blank 2: increase, rise, or gain
If more solute is added to a solvent, more than is able to dissolve at a given temperature, a(n)_____ will be established between dissolved and undissolved solute. The rate at which solute continues to dissolve is_____ to/than the rate at which solute crystallizes from solution.
Blank 1: equilibrium or dynamic equilibrium Blank 2: equal, the same, equivalent, or equal to
A solution forms when the attractive_____ between the solute and solvent are______ in strength to the solvent-solvent and solute-solute attractions and are therefore able to replace them.
Blank 1: forces, interactions, or interaction Blank 2: similar, comparable, close, like, or alike
Entropy (S) is related to the_____ of movement of the particles in a system. The particles of a solid are highly ordered and therefore have______ freedom of movement than the particles of a liquid. A liquid has______ entropy than a solid.
Blank 1: freedom, randomness, amount, or degree Blank 2: less, lower, little, lesser, or restricted Blank 3: more, higher, or greater
In a liquid solution containing two or more volatile components, the mole fraction of the most volatile component will be____ than that of any other component(s) in the vapor above the solution.
Blank 1: higher, greater, more, bigger, or larger
In a liquid solution containing two or more volatile components, the mole fraction of the most volatile component will be_____ than that of any other component(s) in the vapor above the solution.
Blank 1: higher, greater, more, bigger, or larger
Substances that have similar______ forces are able to dissolve in each other, giving rise to the phrase "like______ like."
Blank 1: intermolecular or polar Blank 2: dissolves
A colloid consists of small particles dispersed in a dispersing medium. The small particle size results in a very_____ total surface area; hence colloid particles interact strongly with each other through various_____ forces.
Blank 1: large, big, high, or enormous Blank 2: intermolecular, nonbonding, non-bonding, or adhesive
A solution containing a nonvolatile solute will have a(n)____ vapor pressure than the pure solvent. The change in the vapor pressure is proportional to the_____ fraction of the solute in the solution.
Blank 1: lower, smaller, or lesser Blank 2: mole
An alcohol possesses a(n)_____ hydroxyl (-OH) group and a(n)_____ hydrocarbon chain. Due to its_______ polarity, an alcohol is able to dissolve in both polar and nonpolar solvents.
Blank 1: polar or hydrophilic Blank 2: nonpolar, non-polar, or hydrophobic Blank 3: dual, amphipathic, or mixed
The self-assembly of phospholipids into a lipid bilayer is energetically favorable due to the ion-dipole forces that occur between the______ heads and water at the surface of the bilayer and the______ forces that occur between the nonpolar tails.
Blank 1: polar, ionic, polar-ionic, or hydrophilic Blank 2: dispersion, London dispersion, intermolecular , or London
Water-soluble proteins have_____ exteriors and_____ interiors.
Blank 1: polar-ionic, polar, or hydrophilic Blank 2: nonpolar, hydrophobic, or lipophilic
A solution that contains the maximum amount of dissolved solute in a fixed quantity of solvent at a particular temperature is called a(n)______ solution. This type of solution will have some_____ solute present, which will be in equilibrium with the dissolved solute.
Blank 1: saturated Blank 2: undissolved, solid, or excess
Hydrogen bonding
CH3OH in H2O
Attractions between nonpolar side chains in the protein's interior
Dispersion forces
Dipole-induced dipole
O2 (g) in aqueous solution
A - Polar-ionic head
Organophosphate group or polar-ionic head
Dispersion forces
Present in all solutions; principal intermolecular force when both solvent and solute are nonpolar
Which of the following statements correctly defines colligative properties?
Properties of a solution that depend only on the number of dissolved solute particles
Solvent
The component present in the largest amount
Solute
The component present in the smallest amount
An aqueous solution of KCl (molar mass = 74.55 g/mol) has a molality of 0.25 mol/kg and a density of 1.05 g/mL. Which of the options correctly reflect the steps needed to calculate the molarity (M) of the solution? Select all that apply.
The solution contains 18.6 g of KCl per kg of water. M = 0.25mol KCl0.970L/0.25mol KCl0.970L = 0.26 M
Miscible
The substances are soluble in each other at any quantity
A solution contains 16.5 g naphthalene (C10H8; molar mass = 128.16 g/mol) in 53.3 g of benzene (C6H6; molar mass = 78.11 g/mol). Select all the options that show the correct calculations required to determine the mole fraction of naphthalene.
Xnapthalene = 0.1290.8110.1290.811 = 0.159 moles of benzene = 0.682 mol
Supersaturated
a solution containing more than the equilibrium concentration of solute; the solution is unstable and solute will separate from it readily
The terms "concentrated" and "dilute" describe the relative amounts of dissolved solute in a given solvent. A(n) _____ solution has a smaller amount of solute in the same amount of solvent than a(n) _____ solution.
dilute; concentrated
I2 (s) has a very low solubility in H2O (l) because the weak _____ forces between I2 and H2O are not strong enough to replace the _____ between the H2O molecules.
dipole-induced dipole; hydrogen bonds
The charge density of an ion has a significant effect on its heat of hydration. The _____ the charge on an ion and the _____ its size, the greater its attraction to the H2O molecules surrounding it and the more _____ the value of ΔHhydr of the ion.
higher; smaller; negative
A solution is a _____ mixture, meaning it exists in one phase, whereas a colloid is a _____ mixture with two or more phases in its composition.
homogeneous; heterogeneous
Solvent water molecules will cluster around dissolved ions to form ______, which stabilize the solute in the aqueous solution.
hydration shells
An increase in pressure will cause the solubility of a gas to _____, whereas the solubility of a liquid or solid will usually _____.
increase; not change much
Exterior sugar-phosphate groups
interact with aqueous surroundings via ion-dipole forces.
The nonideal behavior of strong electrolyte solutions is due to electrostatic attractions between ions. Ions of opposite charge "stick together" to form a(n)______ and act as one particle, making its actual concentration seem lower. Select the best answer.
ionic atmosphere
To maintain cell shape, the concentration of particles in the surrounding aqueous solution must be ______ with respect to the concentration of particles in the cell.
isotonic
The ratio mol of soluteL of solution is called the _____ of a solution (symbol M), whereas the _____ (symbol m) of the solution is expressed as mol of solutekg of solvent. For an aqueous solution, these two quantities will be very similar if the solution concentration is _____.
molarity; molality; low
The function of a soap molecule arises from its dual polarity. Its ______ interacts with grease while its ______ interacts with a solvent like water to wash the grease away.
nonpolar "tail"; polar "head"
Proteins that are soluble in water have _____ exteriors and _____ interiors.
polar ionic; nonpolar
If a pure solvent is separated from a solution by a semipermeable membrane, solvent particles will pass through the membrane from the _____ to the _____. This process is called osmosis and the osmotic pressure (Π) is the pressure that must be applied to stop the net flow of solvent.
solvent; solution
The scattering of visible light through a colloid is due to the fact the dispersed particles have particle sizes similar to the wavelengths of visible light. This is referred to as ______.
the Tyndall effect
A phospholipid molecule consists of ______ and a(n) ______ head.
two fatty acid chains; organophosphate group
From left to right across a period
ΔHhydr increases as charge densities increase.
