Physical Chemistry Answers

What is the change in chemical potential of glucose when its concentration in water at 20.0C is changed from 0.10 mol dm^-3 to 1.00 mol dm^-3?

Question 19 : Which of the following mixtures produces a buffer solution?
0.300 M
K
N
O
3
KNO3
+ 0.100 M NaCl (50 mL each)
0.400 M
C
H
3
C
O
O
H
CH3COOH
+ 0.100 M
C
H
3
C
O
O
N
a
CH3COONa
(50 mL each)
0.300 M
N
H
4
C
l
NH4Cl
+ 0.100 M HCl (50 mL each)
0.300 M NaOH + 0.100 M HCl (50 mL each)

Question 20 : The common-ion effect
promotes evaporation.
promotes condensation
reduces ionization.
increases solubility

Question 17 : How many coulombs of charge pass through a cell if 2.40 amperes of current are passed through the cell for 85.0 minutes?
204 C
2120 C
12200 C
0.133 C

Question 18 : Which of the followings is not a Bronsted acid?
HCl

H
2
S
O
4
H2SO4


A
l
C
l
3
AlCl3


H
N
O
3
HNO3

Question 15 : Buffering is:
all of these
due to LeChatelier's Principle
influenced by the common ion effect
is a process that is done by a solution made up of a weak acid and its salt

Question 16 : Which of these is incorrect about the pH of a solution?
pH = -log
[
H
+
]
[H+]

an alkali has a higher pH value than an acid
The higher the pH, the more acidic the solution is
It is a measure of the acidity of the solution

Question 13 : How long would a constant current of 18.0 amperes be required to flow in order for 9000. coulombs of charge to pass through a cell
50 s
0.002 s
200 s
500 s

Question 14 : The conjugate base of HCl is
HOCl

H
+
H+


O
H
−
OH−


C
l
−
Cl−

Question 11 : A substance that is capable of acting as both an acid and as a base is _____.
conjugated
Amphoteric
Diprotic
Binary acid-base

Question 12 : The pH of a neutral solution is
6
8
5
7

Question 9 : For the following reaction, which of the following is a conjugate acid-base pair?
H
C
2
O
−
4
(
a
q
)
HC2O4−(aq)
+
H
2
O
(
l
)
H2O(l)
→
→
H
3
O
+
H3O+
(aq) +
C
2
O
2
−
4
C2O42−
(aq)

H
2
O
H2O
and
C
2
O
4
2
−
C2O42−


H
C
2
O
−
4
HC2O4−
and
H
3
O
+
H3O+


H
C
2
O
−
4
HC2O4−
and
C
2
O
2
−
4
C2O42−


H
C
2
O
−
4
HC2O4−
and
H
2
O
H2O


Question 10 : What’s the concentration of Ag+ ion in a saturated silver chloride solution?
K
s
p
Ksp
= 1.56 x
10
−
10
10−10
.
none of these
0.000339 M
0.0000125 M
4.90 M

Question 7 : A Brønsted-Lowry base is defined as a substance that
decreases [H+] when placed in water.
acts as a proton donor.
increases [H+] when placed in water.
acts as a proton acceptor.

Question 8 : The magnitude of
K
w
Kw
indicates that __________.
water autoionizes very quickly
the autoionization of water is exothermic
water autoionizes very slowly
water autoionizes only to a very small extent

Question 5 : In the following reaction, which is a Brønsted-Lowry base?
H
C
2
O
−
4
(
a
q
)
+
H
2
O
(
l
)
→
H
3
O
+
(
a
q
)
+
C
2
O
2
−
4
(
a
q
)
HC2O4−(aq)+H2O(l)→H3O+(aq)+C2O42−(aq)


H
3
O
+
H3O+


H
2
O
H2O

None of these

H
C
2
O
−
4
HC2O4−


Question 6 : For the following reaction, which of the following is a conjugate acid-base pair?
H
2
P
O
4
−
(
a
q
)
+
N
H
3
(
a
q
)
→
H
P
O
2
−
4
(
a
q
)
+
N
H
+
4
(
a
q
)
H2PO4−(aq)+NH3(aq)→HPO42−(aq)+NH4+(aq)

None of the above

H
2
P
O
−
4
H2PO4−
and
H
P
O
2
−
4
HPO42−


H
2
P
O
−
4
H2PO4−
and
N
H
3
NH3

HPO42- and NH4+