Science

Q: What is the molality of a 20.0% by mass hydrochloric acid solution? The density of the solution is 1.0980 g/mL. A) 0.0220 m B) 6.86 m C) 0.200 m D) 5.68 m E) 6.02 m

Q: A concentrated potassium hydroxide solution is 45.0% KOH by mass and has a density of 1.44 g/mL at 25ºC. The remainder of material is solvent. What is the molality of KOH in the solution?A) 14.6 mB) 8.02 mC) 5.53 mD) 686 mE) 1.02 m

Q: What is the molality of ethanol, C2H5OH, in an aqueous solution that is 51.0% ethanol by mass? A) 1.04 m B) 0.0226 m C) 22.6 m D) 0.719 m E) 53.4 m

Q: What is the molality of a solution that contains 77.7 g of 1,4-dichlorobenzene (C6H4Cl2) in 445 mL of carbon tetrachloride (CCl4)? The density of CCl4is 1.60 g/mL. A) 0.183 m B) 0.743 m C) 0.175 m D) 0.109 m E) 1.90 m

Q: A 3.140 molal solution of NaCl is prepared. How many grams of NaCl are present in a sample containing 2.191 kg of water? A) 243.9 g B) 402.1 g C) 117.7 g D) 688.0 g E) none of these

Q: What is the molality of a solution prepared by dissolving 2.57 g of urea, NH2CONH2, in 57.6g of water?A) 0.0427 mB) 0.0446 mC) 0.0132 mD) 0.743 mE) 0.000711 m

Q: What is the molality of a solution prepared by dissolving 0.244 mol of chloroform, CHCl3, in 456g of toluene, C6H5CH3? A) 0.0642 m B) 0.0469 m C) 0.535 m D) 0.0492 m E) 1.113 m

Q: If 12.7 g of naphthalene, C10H8, is dissolved in 104.6 g of chloroform, CHCl3, what is the molality of the solution? A) 0.0992 m B) 14.5 m C) 0.949 m D) 0.108 m E) 0.113 m

Q: How many moles of urea (60. g/mol) must be dissolved in 77.6 g of water to give a 3.5m solution?A) 2.1 x102molB) 3.5 molC) 0.0035 molD) 0.27 molE) 7.7 x102mol

Q: A 12.0% sucrose solution by mass has a density of 1.05 g/cm3. What mass of sucrose is present in a 30.0-mL sample of this solution? A) 3.78 g B) 3.43 g C) 0.126 g D) 263 g E) 3.60 g

Q: What mass of a solution labeled 6.3% sucrose (C12H22O11, 342 g/mol) by mass contains 15.0g of sucrose? A) 3.4 g B) 39 g C) 240 g D) 0.28 g E) 95 g

Q: What is the percent Na2CO3by mass in a 1.54 molal aqueous solution? A) 0.132% B) 14.0% C) 99.4% D) 16.3% E) 15.4%

Q: What mass of a 26.0% by mass glucose, C6H12O6, solution contains 42.0 g of glucose? A) 46.8 g B) 162 g C) 10.9 g D) 60.7 g E) 42.0 g

Q: What is the molarity of a 20.0% by mass hydrochloric acid solution? The density of the solution is 1.0980 g/mL. A) 6.86 M B) 0.200 M C) 5.68 M D) 6.02 M E) 0.0220 M

Q: The volume of a 15.8% (by mass) solution is 146.4 mL. The density of the solution is 1.084g/mL. What is the mass of solute in this solution? A) 159 g B) 25.1 g C) 1004 g D) 21.3 g E) 134 g

Q: The volume of a 14.4% (by mass) solution is 67.0 mL. The density of the solution is 1.072g/mL. What is the mass of the solution? A) 71.8 g B) 62.5 g C) 1030 g D) 103 g E) 10.3 g

Q: The mass of a 12.0% (by mass) solution is 8.82 g. The density of the solution is 1.120g/mL. What is the mass of the water in this solution? A) 7.76 g B) 10 g C) 1.19 g D) 0.00774 g E) 8.69 g

Q: What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 25.0 m? The density of the solution is 1.5290 g/mL. A) 0.0612% B) 68.9% C) 1.76% D) 50.0% E) 0.654%

Q: What is the mass percent of an aqueous sodium hydroxide solution in which the molarity of NaOH is 4.37 M? The density of the solution is 1.1655 g/mL. A) 0.267% B) 15.0% C) 5.09% D) 1.53% E) 68.9%

Q: What is the mass percent of an aqueous sodium hydroxide solution in which the mole fraction of NaOH is 0.231? The density of the solution is 1.4339 g/mL. A) 40.0% B) 6.21% C) 68.9% D) 33.1% E) 6.44%

Q: A concentrated perchloric acid solution has a density of 1.67 g/mL at 25ºC and is 11.7 M. What is the percent by mass of HClO4in the solution?A) 70.4% HClO4by massB) 0.702% HClO4by massC) 1.42% HClO4by massD) 0.699% HClO4by massE) 60.2% HClO4by mass

Q: A concentrated phosphoric acid solution is 85.5% H3PO4by mass and has a density of 1.69 g/mL at 25ºC. What is the molarity of H3PO4?A) 14.7 MB) 0.166 MC) 5.16 MD) 19.4 ME) 0.0516 M

Q: A concentrated potassium hydroxide solution is 45.0% KOH by mass and has a density of 1.44 g/mL at 25ºC. What is the mass of KOH per L of solution?A) 648 g KOH/L solnB) 0.00144 g KOH/L solnC) 313 g KOH/L solnD) 0.320 g KOH/L solnE) 3.13 g KOH/L soln

Q: A concentrated sulfuric acid solution is 65.0% H2SO4 by mass and has a density of 1.55 g/mL at 20ºC. What is the mass of 3.00 L of the concentrated sulfuric acid solution?A) 1.95 kgB) 3.00 kgC) 7.15 kgD) 1.26 kgE) 4.65 kg

Q: What is the mass of H2SO4 in a 49.5-cm3sample of concentrated sulfuric acid that has a density of 1.84 g/cm3and consists of 98.3% H2SO4?A) 48.7 gB) 89.5 gC) 3.65 gD) 1.81 gE) 26.4 g

Q: What mass of an aqueous 22.9% sodium chloride solution contains 99.5 g of water? A) 129 g B) 29.6 g C) 0.500 g D) 22.8 g E) 99.5 g

Q: Which of the following concerning the topic of concentration is/are correct? 1) A 5.0 molal HCl solution consists of 5.5 moles HCl dissolved in 1.0 kg of solution. 2) The mass percent and mole percent of a particular component in a solution are identical. 3) The mole fraction of a component in a solution may never be greater than 1. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) none of the above

Q: Which of the following concerning the topic of concentration is/are correct? 1) A concentrated solution of hydrochloric acid has a molarity of 12 M. This means that 12 moles of HCl are dissolved in 1.0 L of water. 2) The molality of a solution is unaffected by changes in temperature, even though the total volume of the solution may change significantly. 3) When calculating a mass percent, the "mass of solution" is equal to the sum of the masses of all solution components. A) 1 only B) 2 only C) 3 only D) 2 and 3 E) 1, 2, and 3

Q: The molality of a solution is defined as A) moles of solute per liter of solution. B) the gram molecular weight of solute per kilogram of solvent. C) moles of solute per kilogram of solvent. D) grams of solute per liter of solution. E) moles of solute per kilogram of solution.

Q: The molarity of a solution is defined as the A) moles of solute per liter of solvent. B) moles of solute per kilogram of solution. C) moles of solute per mole of solution. D) moles of solute per kilogram of solvent. E) moles of solute per liter of solution.

Q: The molarity of a solution is defined as the A) moles of solute per liter of solvent. B) grams of solute per kilogram of solvent. C) grams of solute per liter of solution. D) moles of solute per liter of solution. E) moles of solute per kilogram of solvent.

Q: As the number of solute particles in a given volume of solution increases, A) the boiling point will increase and the vapor pressure will increase. B) the freezing point will decrease and the vapor pressure will decrease. C) the freezing point will increase and the vapor pressure will increase. D) the boiling point will decrease and the vapor pressure will decrease. E) the osmotic pressure will decrease and the lattice energy will increase.

Q: Which of the following is not a colligative property?A) boiling-point elevationB) osmotic pressureC) gas solubilityD) freezing-point loweringE) vapor-pressure lowering

Q: If the solubility of O2at 0.360 bar and 25ºC is 15.0 g/100 g H2O, what is the solubility of O2at a pressure of 1.72bar and 25ºC?A) 71.7 g/100 g H2OB) 24.2 g/100 g H2OC) 0.319 g/100 g H2OD) 0.0140 g/100 g H2OE) 3.14 g/100 g H2O

Q: Henry's Law constant is 0.00060 mol/kg"¢bar and 0.0013 mol/kg·bar for N2 and O2 respectively at 25ºC. What pressure of O2 is required to achieve the same solubility as 0.616 bar of N2?A) 0.28 barB) 1.3 barC) barD) barE) 3.5 bar

Q: According to the National Institute of Standards webbook, the Henry's Law constant for N2 gas is 0.00060 mol/kg-bar at 25ºC What is the Henry's law constant in units of mol/kg-atm? (1 bar = 0.9869 atm; 1 atm = 760 mmHg)A) mol/kg.atmB) mol/kg.atmC) mol/kg.atmD) mol/kg.atmE) mol/kg.atm

Q: At a particular temperature the solubility of O2 in water is 0.590 g/L at an oxygen pressure of around 14.7 atm. What is the Henry's law constant for O2(in units of L·atm/mol)?A) 4.01 x10-2B) 7.97 x102C) 2.71 x10-1D) 1.25 x10-3E) None of the above are within 5% of the correct answer.

Q: The solubility of a gas in a liquid can always be increased byA) decreasing the pressure of the gas above the solvent.B) increasing the pressure of the gas above the solvent.C) increasing the temperature of the solvent.D) decreasing the polarity of the solvent.E) decreasing the temperature of the gas above the solvent.

Q: Which of the following is a correct statement of Henry's law? A) The concentration of a gas in solution is directly proportional to the mole fraction of solvent. B) The concentration of a gas in solution is inversely proportional to temperature. C) The concentration of a gas in solution is independent of pressure. D) The concentration of a gas in a solution is inversely proportional to pressure. E) none of these

Q: How does the solubility of a gas in a solvent depend on pressure and temperature? A) Increasing the partial pressure of the gas while increasing the temperature increases the solubility of the gas. B) Decreasing the partial pressure of the gas while decreasing the temperature increases the solubility of the gas. C) Increasing the partial pressure of the gas while decreasing the temperature increases the solubility of the gas. D) Decreasing the partial pressure of the gas while increasing the temperature increases the solubility of the gas. E) Gas solubility is unaffected by pressure or temperature.

Q: Which of the following affect(s) the solubility of gases in solvents? 1) the nature of the gas 2) the nature of the solvent 3) the temperature of the solvent A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Consider the following gas-liquid equilibrium for an aqueous system at a constant partial pressure of N2.N2(g) N2(aq)What is the effect on the equilibrium composition of the liquid when the temperature of the liquid is increased?A) The amount of N2 dissolved in the liquid increases.B) The amount of N2 dissolved in the liquid decreases.C) The amount of N2 dissolved in the liquid does not change.D) Not enough information is provided to answer the question.E) Either A or B could occur.

Q: Consider the following gas-aqueous liquid equilibrium for a closed system at a constant temperature.O2(g) O2(aq)What is the effect on the equilibrium composition of the liquid when the partial pressure of O2 gas above the liquid is increased?A) The amount of O2dissolved in the liquid increases.B) The amount of O2dissolved in the liquid decreases.C) The amount of O2dissolved in the liquid does not change.D) Not enough information is provided to answer the question.E) Either A or B.

Q: Which of the following concerning the effects of temperature and pressure on solubility is/are correct? 1) All gases become more soluble in a liquid at a fixed pressure when the temperature of the liquid is increased. 2) The dissolution of an ionic compound in water may be exothermic or endothermic, depending on the initial temperature of the solution. 3) The solubility of a liquid in water generally is significantly effected by pressure changes of the system. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) none

Q: Which of the following correctly states the relationship between the solubility of a substance in water and temperature? A) The solubility of a substance in water increases as the temperature rises, especially for gases. B) The solubility of a substance in water decreases as the temperature lowers, especially for gases. C) The relationship between the solubility of a substance in water and temperature cannot be accurately predicted, especially for ionic solids. D) The solubility of a substance in water decreases as the temperature rises, especially for ionic solids. E) Two of these are correct.

Q: Which of the following statements best describes what happens when a small amount of solid rubidium bromide is dissolved in water? A) The heat from the warm water melts the solid, making it a liquid. B) Nothing happens, because rubidium bromide is insoluble in water. C) The solid RbBr breaks apart into separate Rb and Br atoms by interacting with the water molecules. D) The water molecules surround each ion in the solid RbBr, separating the Rb ions from the Br ions. E) The solid undergoes a chemical change by reacting with the water.

Q: Which of the following favor(s) the solubility of an ionic solid in a liquid solvent? A) a small magnitude of the lattice energy of the solute B) a large magnitude of the solvation energy of the ions C) a large polarity of the solvent D) all of the above E) none of the above

Q: Which of the following sets of conditions favors maximum solubility of an ionic solute in water? A) The enthalpy of hydration of the cation should be equal to the enthalpy of hydration of the anion, regardless of the magnitude of the lattice energy. B) The magnitude of the lattice energy should be small, and the enthalpy of hydration of the ions should be large. C) The magnitude of the lattice energy should be small, and the enthalpy of hydration of the ions should be small. D) The magnitude of the lattice energy should be large, and the enthalpy of hydration of the ions should be small. E) The magnitude of the lattice energy should be large, and the enthalpy of hydration of the ions should be large.

Q: The solubility of 1-hexanol in water is 0.60 g per 100 g of water at 25ºC. What is the maximum amount of 1-hexanol that will dissolve in 5.3 g of water at 25ºC?A) 0.032 gB) 0.11 gC) 0.60 gD) 3.2 gE) 0.0011 g

Q: Which of the following compounds is least soluble in water?A) CH3CH2CH2NH2B) CH3CH2CH2FC) CH3CH(OH)CH3D) CH3CH2COOHE) CH3CH2NHCH3

Q: Which of the following pure liquids is the best solvent for carbon disulfide? A) C6H6(l) B) NH3(l) C) CH3OH(l) D) H2O(l) E) HBr(l)

Q: Which of the following pure liquids is the best solvent for sodium fluoride? A) CCl4(l) B) C2Cl6(l) C) HCl(l) D) BCl3(l) E) PCl5(l)

Q: Which of the following gases is least soluble in water?A) CO2B) SO3C) NH3D) N2E) HCl

Q: In general, which of the following type(s) of solid(s) would exhibit the greatest solubility in a nonpolar solvent? A) network covalent B) nonpolar molecular C) ionic D) metallic E) polar molecular

Q: Which of the following concerning solubility and the solution process is/are correct? 1) Both hydration energies and lattice energies depend on the magnitude of the ion charges and the size of the ions. 2) An initially nonhomogeneous mixture of two miscible liquids, given enough time, will eventually form a solution as a result of random molecular motions. 3) The dissolution of ionic compounds in water depends only on the hydration energy of the ions. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Which of the following concerning solubility and the solution process is/are correct?1) In a saturated solution of a substance, a solution of the substance is in equilibrium with the pure substance.2) Dissolution of a solute stops once saturation of a solvent is achieved.3) Solubility depends in part on the strength of solute-solute and solute-solvent Van der Waals forces.A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 3E) 1, 2, and 3

Q: Suppose a small amount of a solid is added to water and, after a short time, all the solid has dissolved. Which of the following statements is mostlikely to be true? A) The solution is supersaturated with solute. B) The solution is saturated with solute. C) The solution is unsaturated with solute. D) The solution is either unsaturated or supersaturated with solute. E) The solution is either saturated or supersaturated with solute.

Q: Which of the following concerning solutions is/are correct? 1) For a solution to form, the solvent and solute must be miscible. 2) A solution may be homogeneous or heterogeneous. 3) A colloid is a type of solution. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Which of the following concerning solutions is/are correct? 1) The solvent in a mixture of gases is generally considered to be the substance in greater amount. 2) The solid dissolved in a solution is known as the solute. 3) Solid solutions are called alloys. A) 1 only B) 2 only C) 3 only D) 1 and 2 E) 1, 2, and 3

Q: Synthetic detergent dispersed in water is an example of a(n) A) micelle. B) hydrophilic colloid. C) coagulant. D) hydrophobic colloid. E) association colloid.

Q: A suspension of sodium dodecanoate, CH3(CH2)10COONa, in water is most likely to form what type of colloid? A) hydrophilic colloid B) association colloid C) emulsion D) aerosol E) hydrophobic colloid

Q: Which of the following statements describes the process of coagulation? A) The dispersed phase of an association colloid aggregates and forms a hydrophilic colloid. B) The continuous phase of a colloid aggregates and separates from the dispersed phase. C) The dispersed phase of an association colloid aggregates and forms a hydrophobic colloid. D) The dispersed phase of a colloid aggregates and separates from the continuous phase. E) The dispersed phase of an association colloid aggregates and forms a micelle.

Q: A suspension of silver particles in water is most likely to form what type of colloid? A) aerosol B) micelle C) hydrophobic colloid D) association colloid E) hydrophilic colloid

Q: When a liquid is dispersed in another liquid, the resulting colloid is called a(n) A) emulsion. B) sol. C) foam. D) aerosol. E) gel.

Q: What type of colloid is formed when a solid is dispersed in a liquid? A) emulsion B) gel C) aerosol D) sol E) foam

Q: What type of colloid is formed when a liquid is dispersed in a solid? A) emulsion B) gel C) sol D) foam E) aerosol

Q: What type of colloid is formed when a gas is dispersed in a solid? A) foam B) aerosol C) sol D) emulsion E) gel

Q: What type of colloid is formed when a liquid is dispersed in a gas? A) foam B) emulsion C) aerosol D) sol E) gel

Q: The molal boiling-point constant for water is 0.51ºC/molal. The boiling point of a 1.00m solution of Ca(NO3)2 should be increased byA) exactly 1.53ºC.B) exactly 1.02ºC.C) somewhat less than 1.02ºC.D) exactly 0.51ºC.E) somewhat less than 1.53ºC.

Q: For which of the following aqueous solutions would one expect to have the largest van"t Hoff factor (i)?A) 0.400 m K2SO4B) 0.400 m NaClC) 0.400 m C6H12O6(glucose)D) 0.040 m K2SO4E) 0.040 m NaCl

Q: At 37ºC, what is the osmotic pressure of a 0.59% NaCl by weight aqueous solution? Assume the density of the solution is 1.0 g/mL. (R= 0.0821 L"¢atm/(K"¢mol))A) 0.26 atmB) 2.6 atmC) 3.0 x102atmD) 5.1 atmE) 0.61 atm

Q: Which of the following solutions has the lowest osmotic pressure?A) 0.10 M Al(NO3)3B) 0.20 M C6H12O6C) 0.15 M Ba(NO3)2D) 0.10 M CaCl2E) 0.15 M Na2S

Q: Which of the following solutes, dissolved in 1000 g of water, would provide a solution with the lowest freezing point?A) 0.030 mol of barium chloride, BaCl2B) 0.030 mol of urea, CO(NH2)2C) 0.030 mol of calcium sulfate, CaSO4D) 0.030 mol of acetic acid, CH3COOHE) 0.030 mol of ammonium nitrate, NH4NO3

Q: Which of the following solutes, dissolved in 1.0 kg of water, creates a solution that boils at the highest temperature?A) 0.010 mol H3PO4B) 0.010 mol HClO4C) 0.010 mol H2SO4D) 0.010 mol HClE) 0.010 mol HF

Q: Which of the following amounts of solute, dissolved in 1.0 kg of water, creates a solution with the lowest freezing temperature? (assuming ideal behavior)A) 0.0015 mol of sulfuric acid, H2SO4B) 0.0015 mol of H2SO3C) 0.0030 mol of ethanol, C2H5OHD) 0.0030 mol of methanol, CH3OHE) 0.0015 mol of sucrose, C12H22O11

Q: What is the freezing point of an aqueous 1.66 m CaCl2solution? (Kf for water is 1.858ºC/m.)A) 9.3ºCB) 3.1ºCC) -9.3ºCD) 0.0ºCE) -3.1ºC

Q: Which of the following solutions would have the highest osmotic pressure?A) 0.15 M MgBr2B) 0.15 M NaClC) 0.20 M C12H22O11D) 0.20 M C6H12O6E) 0.20 M CH3OH

Q: Which of the following solutes in aqueous solution would be expected to exhibit the smallest freezing-point lowering (assuming ideal behavior)?A) 0.1 m NaClB) 0.2 m CH3COOHC) 0.05 m Al2(SO4)3D) 0.1 m MgCl2E) 0.25 m NH3

Q: Based on the formulas of the following solutes, which compound would have the smallest van"t Hoff factor (i)? A) Ca(NO3)2(aq) B) K2SO4(aq) C) Th(SO4)2(aq) D) Al2(SO4)3(aq) E) MgSO4(aq)

1 2 3 … 666 Next »

Subjects