1
Prince George’s Community College
CHM 1010(SHAH)
NAME
EXAM 2(100)
I.
Multiple choice: select the best answer for each of the following questions or statements. (40)
1.
Which of the following compounds will NOT conduct electricity when dissolved in water?
a.
C6H12O6
b.
HC2H3O2
c.
KF
d.
NaOH
2. Which type of chemical bond results from sharing valence electrons between two nonmetals?
a.
b.
c.
d.
3.
Which of the following ions has the electron configuration: 1s2 2s2 2p6?
a.
b.
c.
d.
4.
Helium
Neon
Argon
Krypton
How many pairs of nonbonding electrons are there in one molecule of water?
a.
6
Mg2+
Na+
Al3+
All of the above
Which noble gas is isoelectronic with a nitrogen ion?
a.
b.
c.
d.
5.
Ionic bond
Covalent bond
Nonmetallic bond
None of the above
1
b.
2
c.
4
d.
8
State the type of bonds in one molecule of ethylene, C2H4?
a.
b.
c.
d.
5 single bonds
4 single bonds and 1double bond
4 single bonds and 2 double bonds
4 single bonds and 1triple bond
1
2
7.
According to the general trends in the periodic table, which of the following elements is the most
electronegative?
a.
8.
S
XCl
b.
XCl2
c.
X2Cl
d.
XCl3
atm
torr
kPa
N/m2
3.42
b.
0.342
c.
0.292
d.
0.0292
2
b.
3
c.
5
d.
7
boiling point
b.
density
c.
molar mass
Na
b.
Mg
c.
Al
d.
P
-3
b.
3
c.
4
d.
2
Which of the following expresses standard atmospheric pressure?
a.
16.
e.
What is the oxidation state for Nitrogen in NO2- ?
a.
15.
P
d.
polarity
e.
S
Which of the following element has the highest Ionization Energy?
a.
14.
d.
Which of the following properties must be similar for two liquids to be soluble?
a.
13.
O
All halogens have the following number of valence electrons:
a.
12.
c.
What is the molarity of a sucrose(C12H22O11) solution that contains 10.0g of sucrose dissolved in 100
mL of solution?
a.
11.
N
What is the unit equal to 1 mm Hg?
a.
b.
c.
d.
10.
b.
If X represents an element that reacts with oxygen to form a compound with the
formula XO, what is the formula if X forms a compound with chlorine?
a.
9.
C
760 cm Hg
b.
760 torr
c.
760 mm d.
None
If a pressure gauge reads 15 torr, what is the pressure in atmosphere(atm)?
a.
0.20
b.
0.020
c.
2
15
d.
760
3
17.
A sample of argon gas at 520 mm Hg expands from 0.150 L to 0.300L. If the temperature remains
Constant, what is the new pressure?
a.
b.
c.
d.
18.
What is the temperature at which an ideal gas occupies zero volume?
a.
19.
b.
0K
c.
273K d.
273°C
e.
-273K
1
b.
2
c.
3
d.
4
d.
16
How many number of orbitals exist in shell when n = 4?
a.
II.
0°C
How many number of orbitals in subshell exists within the n = 2 and l = 1?
a.
20.
260 mmHg
520 mmHg
760 mmHg
1040 mmHg
2
b.
4
c.
8
(a) Write the ground state electron configuration of the following elements and ions. (10)
Zn
Fr
I
K+
Br-
3
4
(b)
Write electron dot structure for the following molecules and polyatomic ions. (10)
[H3O]+
SO2
O3
C2H4
4
5
III.
Solve the following problems
(40)
(a) A 2.75g sample of an unknown gas has volume 2.25L and pressure 735 mmHg at 25° C. What will
be the molar mass of this unknown gas ? ( R = 0.08206L atm mol-1 K-1 )
(b) A weather balloon containing helium with a volume of 410.0 L rises in the atmosphere and is
cooled from 25C to -25C. The pressure on the gas is reduced from 110.0kPa to 25.0 kPa. What is
the volume of the gas at the lower temperature and pressure?
5
6
(c) What is the rate of effusion of uranium hexafluoride(UF6) and oxygen (O2) gas?
6