Question 1

Amphetamines in urine can be confirmed by mass spectroscopy at a concentration of 500 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration in parts per million?

Accepted Answer

The answer of Amphetamines in urine can be confirmed by...

Question 2

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with Xbenzene = 0.600.

Accepted Answer

A) 0.600 
B) 0.678 
C) 0.756 
D) 0.823

Question 3

Arrows in the energy diagram below represent enthalpy changes occurring in the endothermic formation of a solution:
ΔHS1U1B1solnS1U1B0 = enthalpy of solution
ΔHS1U1B1solute-soluteS1U1B0 = enthalpy change involving solute-solute interactions
ΔHS1U1B1solute-solventS1U1B0 = enthalpy change involving solute-solvent interactions
ΔHS1U1B1solvent-solventS1U1B0 = enthalpy change involving solvent-solvent interactions 
-Which arrows represent ΔHsolute-solute and ΔHsolvent-solvent?

Accepted Answer

A) arrow (a)and arrow (b) 
B) arrow (a)and arrow (c) 
C) arrow (a)and arrow (d) 
D) arrow (c)and arrow (d)

Question 4

-What is the approximate boiling temperature of the liquid formed from the condensation of the vapor above a boiling solution that is 0.70 XA and 0.30 XB?

Accepted Answer

A) 50°C 
B) 55°C 
C) 90°C 
D) 100°C

Question 5

If dissociation of MgCl₂ in water were 100%,the van't Hoff factor would be ________;however,for real solutions the van't Hoff factor for MgCl₂ is ________ (greater than,less than)this value.

Accepted Answer

The answer of If dissociation of MgCl₂ in water were...

Question 6

The vapor pressure of water at 25°C is 23.8 mm Hg.The vapor pressure lowering,ΔP,of an aqueous solution containing 0.500 mole fraction NaCl is ________ (equal to,greater than,less than)11.9 mm Hg?

Accepted Answer

The answer of The vapor pressure of water at 25°C...

Question 7

In the process of dissolving ionic compounds,the cations and anions are separated from the crystal lattice and surrounded by an ordered shell of solvent molecules.If the solvent is water,the dissolved ions are said to be

Accepted Answer

A) ionized. 
B) homogenized. 
C) hybridized. 
D) hydrated.

Question 8

In which case should CO2(g)be more soluble in water?

Accepted Answer

A) The total pressure is 5 atm and the partial pressure of CO2 is 0.4 atm. 
B) The total pressure is 3 atm and the partial pressure of CO2 is 0.6 atm. 
C) The total pressure is 1 atm and the partial pressure of CO2 is 0.3 atm. 
D) The total pressure is 1 atm and the partial pressure of CO2 is 0.5 atm.

Question 9

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp =  and decane (bp = 126°C)is shown. 
-Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane,at what approximate temperature will the mixture begin to boil?

Accepted Answer

A) temperature at point a 
B) temperature at point b 
C) temperature at point d 
D) temperature at point f

Question 10

Molarity is defined as ________,whereas molality is defined as ________.

Accepted Answer

The answer of Molarity is defined as ________,whereas molality is...

Question 11

What volume of 3.00 M CH3OH solution is needed to provide 0.500 mol of CH3OH?

Accepted Answer

A) 3.12 mL 
B) 9.38 mL 
C) 167 mL 
D) 150 mL

Question 12

Calculate the freezing point of a solution of 30.0 g methyl salicylate,C7H6O2,dissolved in 800.g of benzene,C6H6.Kf for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

Accepted Answer

A) -1.56°C 
B) 1.56°C 
C) 3.93°C 
D) 7.06°C

Question 13

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔGsoln)is

Accepted Answer

A) negative. 
B) zero. 
C) positive. 
D) either A or C,depending on the ionic compound.

Question 14

When two similar liquids mix to form a solution,the entropy of solution (ΔSsoln)is expected to be

Accepted Answer

A) negative. 
B) zero. 
C) positive. 
D) negative at low temperatures but positive at high temperatures.

Question 15

A 0.020 m aqueous solution containing which solute will have the lowest freezing point?

Accepted Answer

A) LiCl 
B) NaF 
C) KCl 
D) All will have approximately the same freezing point.

Question 16

A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL.What is the molarity?

Accepted Answer

A) 2.56 M CaCl2 
B) 2.91 M CaCl2 
C) 3.50 M CaCl2 
D) 3.93 M CaCl2

Question 17

Arrows in the energy diagram below represent enthalpy changes occurring in the exothermic formation of a solution:
ΔHS1U1B1solnS1U1B0 = enthalpy of solution
ΔHsolute-solute = enthalpy change involving solute-solute interactions
ΔHsolute-solvent = enthalpy change involving solute-solvent interactions
ΔHsolvent-solvent = enthalpy change involving solvent-solvent interactions 
-Which arrows represent ΔHsolute-solute and ΔHsolvent-solvent?

Accepted Answer

A) arrow (a)and arrow (b) 
B) arrow (a)and arrow (c) 
C) arrow (a)and arrow (d) 
D) arrow (c)and arrow (d)

Question 18

Which of the following solutions will have the lowest freezing point?

Accepted Answer

A) 0.010 m Rb I 
B) 0.010 m K2SeO4 
C) 0.035 m CH3OH    
D) 0.015 m SrBr2

Question 19

A solution is made by dissolving 19.5 g of sucrose,C12H22O11,in 117 g of water,producing a solution with a volume of 125 mL at 20°C.What is the expected osmotic pressure at 20°C?

Accepted Answer

A) 11.0 atm 
B) 23.2 atm 
C) 50.0 atm 
D) 58 atm

Question 20

How many grams of KBr are required to make 250.mL of a 0.115 M KBr solution?

Accepted Answer

A) 0.242 g 
B) 2.17 g 
C) 3.42 g 
D) 28.8 g

Exam 12: Solutions and Their Properties

Amphetamines in urine can be confirmed by mass spectroscopy at a concentration of 500 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration in parts per million?

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with X_benzene = 0.600.

-What is the approximate boiling temperature of the liquid formed from the condensation of the vapor above a boiling solution that is 0.70 X_A and 0.30 X_B?

If dissociation of MgCl₂ in water were 100%,the van't Hoff factor would be ;however,for real solutions the van't Hoff factor for MgCl₂ is (greater than,less than)this value.

The vapor pressure of water at 25°C is 23.8 mm Hg.The vapor pressure lowering,ΔP,of an aqueous solution containing 0.500 mole fraction NaCl is ________ (equal to,greater than,less than)11.9 mm Hg?

In the process of dissolving ionic compounds,the cations and anions are separated from the crystal lattice and surrounded by an ordered shell of solvent molecules.If the solvent is water,the dissolved ions are said to be

In which case should CO₂(g) be more soluble in water?

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = and decane (bp = 126°C) is shown. -Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane,at what approximate temperature will the mixture begin to boil?

Molarity is defined as ,whereas molality is defined as .

What volume of 3.00 M CH₃OH solution is needed to provide 0.500 mol of CH₃OH?

Calculate the freezing point of a solution of 30.0 g methyl salicylate,C₇H₆O₂,dissolved in 800.g of benzene,C₆H₆.K_f for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔG_soln) is

When two similar liquids mix to form a solution,the entropy of solution (ΔS_soln) is expected to be

A 0.020 m aqueous solution containing which solute will have the lowest freezing point?

A 3.17 m solution of CaCl₂ in water has a density of 1.24 g/mL.What is the molarity?

Which of the following solutions will have the lowest freezing point?

A solution is made by dissolving 19.5 g of sucrose,C₁₂H₂₂O₁₁,in 117 g of water,producing a solution with a volume of 125 mL at 20°C.What is the expected osmotic pressure at 20°C?

How many grams of KBr are required to make 250.mL of a 0.115 M KBr solution?

Exam 12: Solutions and Their Properties

Amphetamines in urine can be confirmed by mass spectroscopy at a concentration of 500 ng/mL.Assuming a urine density of 1.025 g/mL,what is this concentration in parts per million?

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with Xbenzene = 0.600.

-What is the approximate boiling temperature of the liquid formed from the condensation of the vapor above a boiling solution that is 0.70 XA and 0.30 XB?

If dissociation of MgCl2 in water were 100%,the van't Hoff factor would be ________;however,for real solutions the van't Hoff factor for MgCl2 is ________ (greater than,less than)this value.

The vapor pressure of water at 25°C is 23.8 mm Hg.The vapor pressure lowering,ΔP,of an aqueous solution containing 0.500 mole fraction NaCl is ________ (equal to,greater than,less than)11.9 mm Hg?

In the process of dissolving ionic compounds,the cations and anions are separated from the crystal lattice and surrounded by an ordered shell of solvent molecules.If the solvent is water,the dissolved ions are said to be

In which case should CO2(g) be more soluble in water?

A phase diagram of temperature versus composition for a mixture of the two volatile liquids octane (bp = and decane (bp = 126°C) is shown. -Assume that you start with a mixture containing 0.80 mol of decane and 0.20 mol of octane,at what approximate temperature will the mixture begin to boil?

Molarity is defined as ________,whereas molality is defined as ________.

What volume of 3.00 M CH3OH solution is needed to provide 0.500 mol of CH3OH?

Calculate the freezing point of a solution of 30.0 g methyl salicylate,C7H6O2,dissolved in 800.g of benzene,C6H6.Kf for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔGsoln) is

When two similar liquids mix to form a solution,the entropy of solution (ΔSsoln) is expected to be

A 0.020 m aqueous solution containing which solute will have the lowest freezing point?

A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL.What is the molarity?

Which of the following solutions will have the lowest freezing point?

A solution is made by dissolving 19.5 g of sucrose,C12H22O11,in 117 g of water,producing a solution with a volume of 125 mL at 20°C.What is the expected osmotic pressure at 20°C?

How many grams of KBr are required to make 250.mL of a 0.115 M KBr solution?

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg,respectively.Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with X_benzene = 0.600.

-What is the approximate boiling temperature of the liquid formed from the condensation of the vapor above a boiling solution that is 0.70 X_A and 0.30 X_B?

If dissociation of MgCl₂ in water were 100%,the van't Hoff factor would be ;however,for real solutions the van't Hoff factor for MgCl₂ is (greater than,less than)this value.

In which case should CO₂(g) be more soluble in water?

Molarity is defined as ,whereas molality is defined as .

What volume of 3.00 M CH₃OH solution is needed to provide 0.500 mol of CH₃OH?

Calculate the freezing point of a solution of 30.0 g methyl salicylate,C₇H₆O₂,dissolved in 800.g of benzene,C₆H₆.K_f for benzene is 5.10°C/m and the freezing point is 5.50°C for benzene.

When an ionic solute dissolves in water to form an unsaturated solution,the free energy change (ΔG_soln) is

When two similar liquids mix to form a solution,the entropy of solution (ΔS_soln) is expected to be

A 3.17 m solution of CaCl₂ in water has a density of 1.24 g/mL.What is the molarity?

A solution is made by dissolving 19.5 g of sucrose,C₁₂H₂₂O₁₁,in 117 g of water,producing a solution with a volume of 125 mL at 20°C.What is the expected osmotic pressure at 20°C?