Chemistry Chapter 11,14,15 Test

Front 1

A sample of vinegar has a hydronium-ion concentration of 7.5 x 10-3 M. What is the pH of vinegar?

Back 1

pH = 2,12.

Front 2

A solution of washing soda has a hydroxide-ion concentration of 0.0040 M. What is the pH at 25°C?

Back 2

pH = 11,60.

Front 3

The pH of a cup of coffee at 25° C was found to be 5.12. What is the hydronium-ion concentration?

Back 3

[H3O+] = 7.6 x 10^−6 M.

Front 4

Would Boric acid, B(OH)3, be more soluble in ethanol, C2H5OH, or benzene, C6H6?

Back 4

Boric acid would be more soluble in ethanol because this acid is polar and is more soluble in a more polar solvent. It can also hydrogen-bond to ethanol but not to benzene.

Front 5

What is the molality of Lauryl alcohol, C12H25OH, in a solution of 17.1g lauryl alcohol dissolved in 165g ethanol, C2H5OH?

Back 5

0.556 m.

Front 6

An antiseptic solution contains hydrogen peroxide, H2O2, in water. The solution is 0.600m H2O2. What is the mole fraction of hydrogen peroxide?

Back 6

0,0107.

Front 7

An aqueous solution of oxalic acid, H2C2O4, is 0.580m. The density of the solution is 1.022g/ml. What is the molar concentration?

Back 7

0.56 M.

Front 8

A solution of vinegar is 0.763M acetic acid, HC2H3O2. The density of the vinegar is 1.004g/ml. What is the molal concentration of acetic acid?

Back 8

0.796 m.

Front 9

Suppose a small amount of a solid is added to water and, once equilibrium is reached, all the solid has dissolved. Which of the following statements is most likely to be true?
a) The solution is supersaturated with solute.
b) The solution is either unsaturated or supersaturated with solute.
c) The solution is either saturated or supersaturated with solute.
d) The solution is unsaturated with solute.
e) The solution is saturated with solute.

Back 9

d

Front 10

In general, which of the following types of solids would be the most soluble in carbon disulfide, CS2?
a) ionic
b) polar molecular
c) nonpolar molecular
d) network covalent
e) metallic

Back 10

c

Front 11

Which of the following gases is least soluble in water?
a) CO2
b) SO3
c) N2
d) NH3
e) HCl

Back 11

c

Front 12

The solubility of a gas in a liquid can always be increased by
a) increasing the temperature of the solvent.
b) decreasing the polarity of the solvent.
c) decreasing the temperature of the gas above the solvent.
d) decreasing the pressure of the gas above the solvent.
e) increasing the pressure of the gas above the solvent.

Back 12

e

Front 13

Which of the following is not a colligative property?
a) freezing-point lowering
b) boiling-point elevation
c) solute solubility
d) osmotic pressure
e) vapor-pressure lowering

Back 13

c

Front 14

If 12.9 g of naphthalene, C10H8, is dissolved in 115.6 g of chloroform, CHCl3, what is the molality of the solution?
a) 0.101 m
b) 0.104 m
c) 0.872 m
d) 13.3 m
e) 0.100 m

Back 14

c

Front 15

What is the mole fraction of urea, CO(NH2)2, in a solution prepared by dissolving 5.2 g of urea in 32.4 g of methanol, CH3OH?
a) 0.079
b) 0.92
c) 0.14
d) 0.86
e) 0.23

Back 15

a

Front 16

The fact that the boiling point of a pure solvent is lower than the boiling point of a solution of the same solvent is a direct consequence of the
a) vapor pressure of the solution being higher than the vapor pressure of the pure solvent.
b) vapor pressure of the solution being lower than the vapor pressure of the pure solvent.
c) osmotic pressure of the solvent being higher than the osmotic pressure of the solution.
d) osmotic pressure of the solvent being lower than the osmotic pressure of the solution.
e) freezing-point depression of the solution.

Back 16

b

Front 17

A red blood cell placed in pure water will swell because
a) the osmotic pressure is greater in the water than in the cell.
b) the osmotic pressure is greater in the cell than in the water.
c) the osmotic pressure is the same in the cell and the water.
d) water moves from a higher osmotic pressure to a lower osmotic pressure.
e) the vapor pressure of the water in the cell is greater than the vapor pressure of pure water.

Back 17

b

Front 18

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 HCl
b) 0.010 mol HF
c) 0.010 mol HClO4
d) 0.010 mol H2SO4
e) 0.010 mol H3PO4

Back 18

d

Front 19

Which of the following species is not capable of acting as an Arrhenius acid?
a) H2SO3
b) HSO3–
c) SO32–
d) H2O
e) H3O+

Back 19

c

Front 20

Which are the Brønsted–Lowry bases in the following equilibrium?
HCOO–(aq) + H2O(l) →HCOOH(aq) + OH–(aq)
a) HCOO– and HCOOH
b) HCOO– and OH–
c) H2O and OH–
d) H2O and HCOOH
e) H2O, HCOOH, and OH–

Back 20

a

Front 21

What is the conjugate acid of H2PO4–(aq)?
a) H3O+
b) H3PO4
c) HPO42–
d) H3P
e) PO43–

Back 21

b

Front 22

Which of the following species is not amphiprotic?
a) N2H62+
b) N2H5+
c) H2PO4–
d) HPO42–
e) HSO3–

Back 22

a

Front 23

Which of the following species cannot act as a Lewis base?
a) S2–
b) SH–
c) Al3+
d) H2O
e) H2S

Back 23

c

Front 24

The concentration of H3O+ in a solution is 8 × 10-4 M at 25ºC. What is its hydroxide-ion concentration?
a) 8 × 10-4 M
b) 1 × 10-10 M
c) 2 × 10-10 M
d) 2 × 10-10 M
e) 1 × 10-11 M

Back 24

e

Front 25

A solution has a hydroxide-ion concentration of 0.0050 M. What is the pOH of the solution?
a) 2.3
b) 7.0
c) 11.7
d) 5.3
e) 8.7

Back 25

a

Front 26

What is the pOH of a 0.047 M HI solution?
a) 15.33
b) 1.33
c) 10.94
d) 12.67
e) 3.06

Back 26

d

Front 27

The hydronium-ion concentration of a solution is 4.6 × 10-6 M. What is the pH of the solution?
a) 9.99
b) 5.34
c) 6.55
d) 3.51
e) 2.00

Back 27

b

Front 28

Which one of the following represents the products in a reaction between nitric acid and water?
a. NaNO3(aq) + H2O(l)
b. H3O+(aq) + NO3-(aq)
c. H2(g) + NO2(g) + HO2(l)
d. H2NO3+(aq) + OH-(aq)

Back 28

b

Front 29

A sulfuric acid solution that is 65.0% H2SO4 by mass has a density of 1.55 g/mL at 20°C. What is the
molarity of sulfuric acid in the solution?

Back 29

10,3 M.

Front 30

A 100g sample of a brand of rubbing alcohol contains 65.0g of isopropyl alcohol, C3H7OH, and 35g of water. What is the mole fraction of isopropyl in the solution? What is the mole fraction of water?

Back 30

Alc- 0.358
Water- 0.642

Front 31

What is self-ionization and give an example.

Back 31

The self-ionization of water is the reaction of two water molecules in which a proton is transferred from one molecule to the other to form H3O+ and OH− ions. At 25C, the
Kw expression is Kw = [H3O+][OH−] = 1.0 x 10−14.

Front 32

What is the pH of a solution prepared by dissolving 0.832 g of NaOH(s) in 6.50 L of water?

Back 32

11,51.

Front 33

A buffer solution is prepared by mixing equal concentrations of HClO(aq) and KClO(aq).

a) A small amount of hydronium ion is added to the mixture. Write the chemical equation that illustrates how the buffer system removes the hydronium ion.
b) A small amount of hydroxide ion is added to the mixture. Write the chemical equation that illustrates how the buffer system removes the hydroxide ion.

Back 33

a)ClO-(aq) + H3O+(aq)  HClO(aq) + H2O(l)
b)HClO(aq) + OH-(aq)  ClO-(aq) + H2O(l)