Page path
• CHEM101_MH_V4
• Topic 13: Acids and Bases
Started on Monday, March 28, 2022, 9:26 AM
State Finished
Completed on Monday, March 28,
... [Show More] 2022, 10:05 AM
Time taken 38 mins 38 secs
Grade 105.80 out of 115.00 (92%)
Question 1
Correct
4.60 points out of 4.60
Flag question
Question text
Consider the following four solutions:
• NaCl in water
• Acetic acid in water
• Acetic acid in benzene
• Naphthalene in benzene
Which of these solutions has the strongest solute-solvent interactions and the interaction is of which type?
Select one:
a. Acetic acid in water; hydrogen bonding
b. Acetic acid in benzene; dipole-induced dipole interaction
c. NaCl in water; ion-dipole interaction
d. Naphthalene in benzene; London Dispersion Forces
e. NaCl in water; hydrogen bonding
Question 2
Correct
4.60 points out of 4.60
Flag question
Question text
What states that the solubility of a gas in a liquid is proportional to the pressure of the gas over the solution?
Select one:
a. Entropy
b. Henry's law
c. Dissolution
d. Vapor pressure
e. Enthalpy of salvation
Question 3
Correct
4.60 points out of 4.60
Flag question
Question text
A solution is 40.00% by volume benzene (C6H6) in carbon tetrachloride at 20°C. The vapor pressure of pure benzene at this temperature is 74.61 mmHg and its density is 0.87865 g/cm3; the vapor pressure of pure carbon tetrachloride is 91.32 mmHg and its density is 1.5940 g/cm3. If this solution is ideal, its total vapor pressure at 20°C is
Select one:
a. 84.64 mmHg
b. 84.30 mmHg
c. 82.96 mmHg
d. 81.63 mmHg
e. 165.93 mmHg
Question 4
Correct
4.60 points out of 4.60
Flag question
Question text
Which statement is false?
Select one:
a.
The vapor pressure of a solvent over a solution decreases as its mole fraction increases.
b.
The solubility of a gas increases as the temperature decreases.
c.
The vapor pressure of a solvent over a solution is less than that of pure solvent.
d.
The greater the pressure of a gas over a solution, the greater its solubility.
e.
Ionic solutes dissociate in solution, causing an enhancement of all colligative properties.
Question 5
Correct
4.60 points out of 4.60
Flag question
Question text
Safrole was once used as a flavoring in root beer, until it was banned in 1960. What is the vapor pressure of a solution prepared by dissolving 0.75 mol of nonvolatile safrole in 950 g of ethanol (46.07 g/mol)? P°ethanol = 50.0 torr at 25°C.
Select one:
a. 1.8 torr
b. 11 torr
c. 15 torr
d. 40 torr
e. 48 torr
Question 6
Correct
4.60 points out of 4.60
Flag question
Question text
Which of these compounds is a weak electrolyte?
Select one:
a. HCl
b. NH3
c. C6H12O6 (glucose)
d. N2
e. KCl
Question 7
Correct
4.60 points out of 4.60
Flag question
Question text
What relationship states that the partial pressure of a solvent over a solution is given by the vapor pressure of the pure solvent times the mole fraction of the solvent in the solution?
Select one:
a. Henry's law
b. Law of partial pressures
c. Curie's law
d. Raoult's law
e. Vapor pressure
Question 8
Correct
4.60 points out of 4.60
Flag question
Question text
When 12.1 g of the sugar sucrose (a nonelectrolyte) are dissolved in exactly 800 g of water, the solution has a freezing point of –0.082°C. What is the molar mass of sucrose?
(Kf of water is 1.86°C/m.)
Select one:
a. 426 g/mol
b. 99.2 g/mol
c. 178 g/mol
d. 266 g/mol
e. 343 g/mol
Question 9
Correct
4.60 points out of 4.60
Flag question
Question text
What is the freezing point of a solution made from 22.0 g of octane (C8H18) dissolved in 148.0 g of benzene?
(For benzene, freezing point = 5.50°C; Kf = 5.12°C/m)
Select one:
a. –1.16°C
b. 0.98°C
c. 6.66°C
d. 12.2°C
e. 5.49°C
Question 10
Correct
4.60 points out of 4.60
Flag question
Question text
What volume of water (d = 1.00 g/mL) should be added to 600. mL of ethanol in order to have a solution that boils at 95.0°C?
(For ethanol, Kb = 1.22 °C/m; density = 0.789 g/cm3; boiling point = 78.4°C)
Select one:
a. 186 mL
b. 245 mL
c. 518 mL
d. 116 mL
e. 322 mL
Question 11
Correct
4.60 points out of 4.60
Flag question
Question text
What is the name for a solute that does not exert a vapor pressure when it is dissolved in a liquid?
Select one:
a. Colloid
b. Amorphous solid
c. Nonvolatile
d. Crystalline solid
e. Electrolyte
Question 12
Correct
4.60 points out of 4.60
Flag question
Question text
The solubility of nitrogen gas in water at 25°C and a nitrogen pressure of 522 mmHg is 4.7 × 10–4 mol/L. What is the value of the Henry's law constant in mol L–1• atm–1?
Select one:
a. 6.8 × 10–4 mol L–1• atm–1
b. 4.7 × 10–4 mol L–1• atm–1
c. 3.2 × 10–4 mol L–1• atm–1
d. 9.0 × 10–7 mol L–1• atm–1
e. 1.5 × 103 mol L–1• atm–1
Question 13
Correct
4.60 points out of 4.60
Flag question
Question text
What is the name given to a solution that contains more solute than it has the capacity to dissolve?
Select one:
a. Unsaturated
b. Saturated
c. Soluted
d. Supersaturated
e. Oversaturated
Question 14
Correct
4.60 points out of 4.60
Flag question
Question text
What mass of ethanol (C2H5OH), a nonelectrolyte, must be added to 10.0 L of water to give a solution that freezes at –10.0°C? Assume the density of water is 1.0 g/mL.
(Kf of water is 1.86°C/m.)
Select one:
a. 85.7 kg
b. 24.8 kg
c. 5.38 kg
d. 2.48 kg
e. 1.17 kg
Question 15
Correct
4.60 points out of 4.60
Flag question
Question text
What is [OH–] for a solution at 25°C that has [H3O+] = 8.23 × 10–2 M?
Select one:
a. 8.23 × 10–2 M
b. 1.22 × 10–6 M
c. 8.23 × 10–12 M
d. 1.22 × 10–13 M
e. 8.23 × 10–16 M
Question 16
Incorrect
0.00 points out of 4.60
Flag question
Question text
A solution is prepared by adding 0.10 mol of iron(III) nitrate, Fe(NO3)3, to 1.00 L of water. Which statement about the solution is correct?
Select one:
a. The solution is basic.
b. The solution is neutral.
c. The solution is acidic.
d. The value of Ka for the species in solution must be known before a prediction can be made.
e. The value of Kb for the species in solution must be known before a prediction can be made.
Question 17
Correct
4.60 points out of 4.60
Flag question
Question text
Which one of these salts will form an acidic solution upon dissolving in water?
Select one:
a. LiBr
b. NaF
c. NH4Br
d. KOH
e. NaCN
Question 18
Correct
4.60 points out of 4.60
Flag question
Question text
Which statement is true regarding the reversible reaction below?
H2CO3+ F– HCO3+ HF.
Ka1(H2CO3) = 4.2 × 10–7; Ka(HF) = 7.1 × 10–4
Select one:
a. At equilibrium, [HF] > [H2CO3] because HF is a stronger acid than H2CO3.
b. At equilibrium, [HF] > [H2CO3] because H2CO3 is a stronger acid than HF.
c. At equilibrium, [HF] = [H2CO3].
d. At equilibrium, [H2CO3] > [HF] because HF is a stronger acid than H2CO3.
e. At equilibrium, [H2CO3] > [HF] because H2CO3 is a stronger acid than HF.
Question 19
Correct
4.60 points out of 4.60
Flag question
Question text
Which of the following is the correct Kb expression for the reaction below?
B(aq) + H2O(l) HB+(aq) + OH–(aq)
Select one:
a. Kb = [B][H2O]
b.
c.
d.
e. Kb = [HB+][OH–]
Question 20
Incorrect
0.00 points out of 4.60
Flag question
Question text
What is the H+ ion concentration in a 2.1 × 10–4 M Ca(OH)2 solution?
Select one:
a. 7.3 × 10–4 M
b. 4.2 × 10–4 M
c. 2.1 × 10–4 M
d. 2.4 × 10–11 M
e. 4.8 × 10–11 M
Question 21
Correct
4.60 points out of 4.60
Flag question
Question text
Which is a basic oxide?
Select one:
a. NO2
b. H2O
c. Na2O
d. SnO
e. SO2
Question 22
Correct
4.60 points out of 4.60
Flag question
Question text
What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 × 10–5]
Select one:
a. 3.74
b. 4.98
c. 6.53
d. 9.02
e. 11.28
Question 23
Correct
4.60 points out of 4.60
Flag question
Question text
In the reaction, HSO4–(aq) + OH–(aq) SO42–(aq) + H2O(l), the conjugate acid-base pairs are
pair 1 pair 2
Select one:
a. HSO4– and SO42–; H2O and OH–.
b. HSO4– and H3O+; SO42 – and OH–.
c. HSO4– and OH–; SO42 – and H2O.
d. HSO4– and H2O; OH – and SO42–.
e. HSO4– and OH–; SO42 – and H3O+.
Question 24
Correct
4.60 points out of 4.60
Flag question
Question text
Which is an acidic oxide?
Select one:
a. P4O10
b. MgO
c. Fe2O3
d. K2O
e. Cr2O3
Question 25
Correct
4.60 points out of 4.60
Flag question
Question text
What is [OH–] for a solution at 25°C that has [H3O+] = 2.35 × 10–3 M?
Select one:
a. 4.26 × 10–5 M
b. 2.35 ×10–11 M
c. 4.26 × 10–12 M
d. 2.35 × 10–17 M
e. 2.35 ×10–3 M [Show Less]