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ACIDS AND BASES QUIZ
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Question 1
Which one of the followig descriptions defines a
strong acid?
It is concentrated.
It does dissociate in
water.
It almost completely
dissociate in water.
It absorbs water from
the air.
Wrong Answer!
A strong acid is almost completely dissociated.
HA(aq)  H+(aq) + A-(aq)
Question 2
Which of the following represents the reaction
between zinc powder and a dilute aqueuous
solution of sulfuric acid?
Zn + H2SO4 ZnSO4 + H2
4Zn + H2SO4 4ZnO +
H 2S
Zn + 2H2SO4 2ZnS +
2H2O + 3O2
Zn + H2SO4 ZnH2 +
SO2 + O2
Wrong Answer!
Metals react with acids to form hydrogen and salt.
Question 3
When the following 1.0 moldm-3 solutions are listed
in increasing order of pH (lowest first), what is
the correct order ?
HNO3<H2CO3<Ba(OH)2<NH3
Ba(OH)2<H2CO3<NH3<HNO3
NH3<Ba(OH)2<H2CO3HNO3
HNO3<H2CO3<NH3<Ba(OH)2
Wrong Answer!
strong acid < weak acid < weak base < strong base
Question 4
The amino acid alanine has the structure:
H2N-CH(CH3)-COOH
Which of the following species represents its
conjugate acid ?
NH2CH(CH3)COO -
+NH
3CH(CH3)COOH
+NH
3CH(CH3)COO
+NH3CH(CH
-
3)COOH 2
+
Wrong Answer!
The conjugate acid is formed by protonation of the amino
group
Question 5
In the equilibrium below, which species represents
a conjugate acid-base pair?
CH2ClCOOH(aq) + H2O(l)
CH2ClCOO-(aq) + H3O+(aq)
H2O/H3O+
CH2ClCOO -/H3O+
H2O/CH2ClCOO -
CH2ClCOOH/H2O
Wrong Answer!
A conjugate acid-base pair differ by a proton (H+)
Question 6
Hydrogen chloride dissolved in water reacts with
magnesium. Hydrogen chloride dissolved in
ethanol does not react with magnesium. Which
statement accounts for this observation?
Hydrogen chloride does
not form ions in water.
Ethanol accepts
hydrogen ions (protons)
and water does not.
Magnesium is very
soluble in ethanol but
insoluble in water.
Water is a hydrogen
ion/proton acceptor
Wrong Answer!
Acid behaviour is observed in water since the water
molecule is a strong base (proton acceptor) and forms
hydronium ions, H3O+.
Question 7
A dilute aqueous solution of benzenecarboxylic
acid (an organic acid) is a poor conductor of
electricity. Which of the following statements
accounts for this observation?
Benzenecarboxylic acid
solution has a high
concentration of ions.
Benzenecarboxylic
acid is only slightly
dissociated in water.
Benzenecarboxylic
acid is completely
dissociated in water.
It is a strong acid.
Wrong Answer!
The low concentration of ions accounts for its low
conductivity.
Question 8
A decrease in the pH of an aqueous solution
corresponds to:
A decrease in the H+
concentration and an increase
in the OH- concentration.
An increase in the OHconcentration and an increase
in the H+ concentration.
An increase in the H+
concentration and a decrease
in the OH- concentration.
A decrease in the H+
concentration with no change
in the OH- concentration.
Wrong Answer!
A decrease in pH correlates to an increase in the
hydrogen ion concentration.
Question 9
Calcium oxide is added to a lake to neutralise the
effects of acid rain. The pH value of the lake
water rises from 4 to 6. What is the change in
concentration of [H+(aq)] in the lake water?
An increase by a
factor of 2.
An increase by a
factor of 100.
A decrease by a
factor of 2.
A decrease by a
factor of 100.
Wrong Answer!
pH and [H+] are inversely related. An increase in the pH
by a value of 1 corresponds to x10 decrease in the H+
Question 10
Which of the ions behave as a BrØnsted – Lowry
base and as a BrØnsted – Lowry acid?
CO32-
HSO4-
NO3-
Such a species
does not exist.
Wrong Answer!
HSO4- SO4- + H+
HSO4- + H+  H2SO4
Question 11
The pH of solution X is 1 and that of Y is 2. Which
statement is correct about the hydrogen ion
concentrations in the two solutions?
that in Y.
[H+] in X is twice
that in Y.
[H+] in X is ten
times that in Y.
[H+] in X is a hundred
times that in Y.
[H+] in X is half
Wrong Answer!
A change in pH of 1 unit corresponds to a change of x10
in the concentration of hydrogen ions.
Question 12
In which of the following reactions does the nitric
acid molecule act as a base?
HNO3 + 2H2SO4 NO2+
+ 2HSO4- + H3O+
HNO3  H+ + NO3-
HNO3 + H2O H3O+ +
NO3-
HNO3 + CH3COOH
CH3COOH2+ + NO3-
Wrong Answer!
The sulfuric acid molecule is deprotonated.
Question 13
Which of the following would exactly neutralise
100cm3 of 1 mol dm-3 sulfuric acid?
0.2 mol Na2CO3
0.1 mol NH3
0.1 mol Ba(OH)2
0.1 mol KOH
Wrong Answer!
H2SO4 + Ba(OH)2  BaSO4 + 2H2O
0.1 mol of sulfuric acid reacts with 0.1 mol of barium
hydroxide.
Question 14
Which is not a strong acid?
Carbonic acid
Nitric acid
Sulfuric acid
Hydrochloric acid
Wrong Answer!
Carbonic acid is a weak acid
Question 15
Which equation correctly describes phosphoric(V)
acid behaving as a monoprotic acid in aqueous
solution?
H3 PO4(aq)
H3 PO4(aq)
2H+(aq)+ HPO42-(aq)
3H+(aq)+ PO43-(aq)
H2 PO4(aq)
H3 PO4(aq)
H+(aq)+ HPO42-(aq)
H+(aq)+ H2PO4-(aq)
Wrong Answer!
A monoprotic acid releases 1 hydrogen ion per molecule
in water.
Question 16
Ammonia molecules in aqueous solution can be
considered as:
A Lewis acid (only)
A Lewis base (only)
A BrØnsted – Lowry
base (only)
Both a BrØnsted – Lowry
base and a Lewis base
Wrong Answer!
The ammonia molecule has an available lone pair of
electrons and is able to accept a hydrogen ion and form
the ammonium ion (via a dative bond form).
Congratulations!
You have completed the quiz!