15-item test on acids and bases

1. Instruction
Questions and Answers
Rationale

2. Instruction
• There are 15 questions provided.
• The questions are in a TRUE or FALSE and Multiple Choice
type of test.
• Choose the BEST answer of each question. Just click the
word/s or letter of your desired answer.
• After each question, an explanation is given to aid
understanding. Click the icon [ ].
• To return, click . Click to proceed to the next page.
• Answer HONESTLY.

3. Bases as defined by Arrhenius are
Electron pair donors
Proton acceptors
Substance that produce hydrogen ions in aqueous solution
Substance that produce hydroxide ions in aqueous solution
All of the above

4. An example of a strong acid is
dilute nitric acid
concentrated acetic acid
carbonic acid
citric acid
H2O

5. A given substance is an acid if in
aqueous solution the substance
has a pH above 7
has a soapy feeling
turns litmus paper red
reacts with a metal
is colorless

6. Pure water is neutral.

7. Which is NOT a base?
Mg(OH)2
BF3
H2O
NH3
KOH

8. Which of the following statements
is TRUE for all bases?
Bases consist of oxides and hydroxides of metals.
When bases react with acids, the only product is salt.
Bases are colorless.
Bases turn phenolphthalein from colorless to pink.
Bases taste sour.

9. The color of phenolphthalein in an
acid is colorless.

10. Indicators used in titration are
added to
the titrator
the acid only
the base only
both acid and base
the acid or base

11. A standard solution is one
which is basic in nature
which is acidic in nature
whose concentration is being tested
with known concentration
which is added to the titrand

12. NH4+ is a Lewis base.

13. Calculate the pH of 0.0001 M HCl
solution.
7
12
1
4
2

14. Blood has an acidic pH.

15. An acid found in the stomach is
CH3COOH
HNO3
HCL
H2SO4
H2CO3

16. A pH of 2 is more acidic than a pOH of
12.

17. When the hydrogen ion (H+) is indicated
in connection with its water solution,
the ion represented is
OH-
H2O+
H2O2+
H3O+
None of the above

19. Bases as defined by Arrhenius are
D. Substance that produce hydroxide ions in aqueous solution
An Arrhenius base is a substance upon dissociation in water
causes an increase in the concentration of the solvent
anion, OH+.

20. An example of a strong acid is
A. dilute nitric acid
There are only six strong acids:
HCl - hydrochloric acid
HNO3 - nitric acid
H2SO4 - sulfuric acid
HBr - hydrobromic acid
HI – hydroiodic acid (also known as hydriodic acid)
HClO4 - perchloric acid

21. A given substance is an acid if in
aqueous solution the substance
C. turns litmus paper red
An acid is a substance whose water solution exhibits the
following properties:
1. turns litmus paper red
2. has a sour taste
3. neutralizes bases
4. reacts with active metals to produce hydrogen gas

22. Pure water is neutral.
TRUE
In pure water, (H3O+) or more often represented as [H+], is
1.0x10-7 M, and the [OH-] is also 1.0x10-7 M. since [H+] is
equal to [OH-], then water is considered neutral.

23. Which is NOT a base?
B. BF3
BF3 is a Lewis acid. Mg(OH)2, NH3 and KOH are bases. H2O is
amphoteric, it can act as an acid or a base.

24. Which of the following statements is
TRUE for all bases?
D. Bases turn phenolphthalein from colorless to pink.
Solutions of bases have slippery, soapy feeling and a biting,
bitter taste. Like acids, bases also react with indicators.
Bases turn red litmus blue, turn methyl orange from red to
yellow, and turn phenolphthalein from colorless to pink.
Bases neutralize acids to form water and a salt. Bases have
hydroxide ion concentration.

25. The color of phenolphthalein in an
acid is colorless.
TRUE
Phenolphthalein is often used in titrations, it turns colorless
in acidic solutions and pink in basic solutions. If the
concentration of indicator is particularly strong, it can
appear purple.

26. Indicators used in titration are
added to
E. the acid or base
An indicator is added to the titrand (either an acid or a
base), whose concentration is unknown.

27. A standard solution is one
D. with known concentration
A standard solution is a solution containing a precisely
known concentration of an element or a substance.
Standard solutions are used to determine the concentrations
of other substances, such as solutions in titrations.

28. NH4+ is a Lewis base.
FALSE
NH4+ is a Lewis acid. It donates one proton (H+).
H2O + NH4+ <--> H3O+ + NH3

29. Calculate the pH of 0.0001 M HCl
solution.
D. 4
Given:
[H+] = 0.0001 M
[H+] = 10-4
Solution:
pH = - log [10-4]
pH = - (-4)
pH = 4

30. Blood has an acidic pH.
FALSE
The pH of blood is 7.35 – 7.45.
pH < 7.00 acidic solution
pH = 7.00 neutral solution
pH > 7.00 basic solution
Therefore, blood has a slightly basic pH.

31. An acid found in the stomach is
C. HCL
Hydrochloric acid, normally found in the gastric juices, is
necessary for the proper digestion of proteins in the
stomach.

32. A pH of 2 is more acidic than a pOH
of 12.
FALSE
pOH is a measure of the concentration of hydroxide ions.
pOH = 14 – pH
pOH = 14 – 2
pOH = 12
Therefore, a pH of 2 is equal to a pOH of 12.

33. When the hydrogen ion (H+) is indicated
in connection with its water
solution, the ion represented is
D. H3O+
Hydronium ion (H3O+) is responsible for the observed properties
of acids in water. For the sake of simplicity, H+ is often use
instead of the more accurate H3O+. For aqueous solutions,
whenever H+ is written, it should be understood as H3O+.