AnswersS1S Chemistry B E4912 - AGUnit Test

Unit Test — Unit test Answers

24 verified answers1 views
1
Free Preview

Which description correctly characterizes the acidity or basicity of a solution?

A
The higher the pH is, the more the hydroxide ion concentration decreases and the more acidic the solution becomes.
B
The higher the pH is, the more the hydroxide ion concentration increases and the more basic the solution becomes.
C
The lower the pH is, the more the hydronium ion concentration decreases and the more acidic the solution becomes.
D
The lower the pH is, the more the hydronium ion concentration increases and the more basic the solution becomes.
2
Free Preview

Consider the reaction below.NH4+ + H2O NH3 + H3O+Which is an acid-conjugate base pair?

Question illustration
A
NH4+ and NH3
B
NH4+ and H3O+
C
H2O and NH3
D
H2O and H3O+
3

What type of substance reacts with limestone (CaCO3) and produces carbon dioxide gas?

A
a neutral substance
B
a base
C
an acid
D
both an acid and a base
4

Lewis acids and bases are most closely associated with which process?

A
proton transfer
B
electron transfer
C
the formation of aqueous ions
D
the formation of a conjugate acid or base
5

Which of these correctly defines the pOH of a solution?

A
the log of the hydronium ion concentration
B
the negative log of the hydronium ion concentration
C
the log of the hydroxide ion concentration
D
the negative log of the hydroxide ion concentration
6

An unknown substance turns blue litmus paper to red. Which additional test could be used to confirm the substance’s identity?

A
It should turn phenolphthalein from colorless to pink because it is a base.
B
It should turn phenolphthalein from pink to colorless because it is a base.
C
It should turn methyl orange to orange because it is an acid.
D
It should turn methyl orange to red because it is an acid.
7

Soaps feel slippery on our hands because they dissolve the oil on our skin, decreasing friction.This is because soap contains

A
a neutral molecule.
B
a salt molecule.
C
an acid.
D
a base.
8

A solution of HCl has = 0.01 M. What is the pH of this solution?Use .

Question illustration
A
–2
B
–1
C
1
D
2
9

What is the definition of a Lewis base?

A
a substance that donates a proton
B
a substance that donates electrons to form a covalent bond
C
a substance that accepts electrons to form a covalent bond
D
a substance that when dissolved in water increases hydrogen ion concentration
10

A solution of ammonia has a pH of 11.8. What is the concentration of OH– ions in the solution?Useful formulas include , , , and .

Question illustration
A
1.58 10–12 M
Option A
B
6.31 10–3 M
Option B
C
2.20 M
D
158 M
11

Which of the following substances is an Arrhenius acid?

A
BF3
B
HCN
C
NH3
D
Mg(OH)2
12

Which pair of substances would most likely result in the production of a gas when reacting with an acid?

A
litmus and methyl orange
B
base and salt
C
metal and carbonate
D
carbon dioxide and water
13

Consider the reaction below.HF + H2O H3O + FWhich is an acid-conjugate base pair?

Question illustration
A
HF and H3O+
B
HF and F
Option B
C
H2O and HF
D
H2O and F
Option D
14

Which of these substances contributes to soap’s slippery texture?

A
an acid
B
a base
C
carbonate
D
water
15

How can the pH of a solution be calculated if the pOH is known?

A
by taking the negative logarithm of pOH
B
by adding the pOH to 14
C
by raising 10 to the power of –pOH
D
by subtracting the pOH from 14
16

A substance with a high [H+ ] would likely have which additional characteristics?

A
a high [OH– ] and a high pOH
B
a low [OH– ] and a high pOH
C
a high [OH– ] and a low pOH
D
a low [OH– ] and a low pOH
17

Which is a characteristic of a Lewis base?

A
It behaves as the electron donor.
B
It behaves as the electron acceptor.
C
It donates a hydrogen ion to other compounds.
D
It increases the concentration of hydrogen ions.
18

Which of the following best defines an acid?

A
An acid has a pH of 7.
B
An acid has hydroxide ions.
C
An acid has fewer positive ions in solution.
D
An acid has more hydrogen ions in solution.
19

Which would most likely be the pH of a highly-corrosive acid?

A
1
B
5
C
8
D
11
20

What is the equilibrium constant of pure water at 25°C?

A
1014
B
10–14
C
10–7
D
107

Did you find these answers helpful?

More from this Course

Quiz
25 verified answers

Unit Test

Quiz
10 verified answers

Neutralization Reactions

Quiz
8 verified answers

Titration Reactions