General Chemistry (CHMS2101)
BSc, Biochemistry - BCHS
Semester: First Semester
Level: 200
Year: 2016
FACULTY OF SCIENCE
CA CHMS2101 GENERAL CHEMISTRY 20
TH
FEBUARY 2016
Name: ____________________________Program: _____________Matr
________________
1.Define the de Broglie associated wavelength……………………………………
Calculate the ratio of the de Broglie wavelength (λn) of an electron to that of a neutron (λ
2
)
.Given that the two move with the same velocity and that m
n
=
1836m
e
…………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………
2. Which quantum number is not obtained from the solution of the Scrhodinger equation?
…………………………………………………………………………………………
3. What is the number of electrons on the 3d sub-shell of the element whose atomic number is
26? ……………………………………………………..
4. You can expect the emission spectrum of the ion He
4
to be similar to the spectrum of which
element? ………………………..What is your explanation? …………………………
5.Does the set of four quantum numbers (1,1,0, +
1
2
) refer to an
electron?....................................Explain………………………………………………………
…………………………….
6. All of the following are true, except …………………….
a) An ion has a positive or negative charge
b) Metals tend to form positive ions.
c) Ions are formed by adding electrons to a neutral atom.
d) ions are formed by changing the number of neutrons in an atom's nucleus
e) Ions are formed by removing electrons from a neutral atom
7. Which one of the following statements about atomic structure is false?
a) The electrons occupy a very large volume compared to the nucleus
b) Almost all of the mass of the atom is concentrated in the nucleus
c) The number of protons and neutrons is always equal for all atoms of an element
d) Electrons exist in quantized energy levels.
e) The protons and neutrons in the nucleus are very tightly packed
8. What is the orbital diagram for the most stable ion of the element magnesium,
12
Mg?..............................................................................................................
9. Passing an electric current through a certain substance produces oxygen and sulfur. This
substance cannot be a
……………………………………………………………………………….
a) Pure substance ; b) compound; c) mixture; d) element; e) any of the above.
10. Which one of the following is an extensive property? …………………………………..
a) freezing point; b) density; c) mass; d) boiling point; e) temperature
11. Which one of the following is a non-metal?........................................................
76
X; b)
74
W; c)
38
Z; d)
38
Z; e)
35
U
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12. Use the following information to identify the atom or ion: 8 protons, 8 neutrons and 10
electrons
a) S
2+
; b) O
2-
; c) O
2+
;d) S
2-
; e) Ne
13. Calculate the wavelength of the radiation that an energy of 3.6xl0
47
joules given that h =
6.63x10
-34
J s and c = 2 xl0
8
m/s…………………………………
a) 1.8x10® m; b) 5.5 m^5.5 nm; d) 5.5xW
16
m; e) 2.3x10
s
® m
14. Which one of the following electron transmissions in the hydrogen atom results in the
greatest release o f energy from the hydrogen atom?
a) n = 3 to n = 4; b) n = 6 to n = 4;(c) n = 1 to n = 3 d) n = 7 to n = 5; e) Transitions c and d
result equally in greatest release
15. Which orbital is represented by the quantum numbers n = 3, l= 0, m
l
= 0?
16. An electron in which one of the following sub shells experiences the greatest effective
nuclear charge in a many-electron atom? …………………………………………
a) 4f; b) 4p; c) 4d; d) 4s ) They all experience the same effective nuclear charge
17) Which form of electromagnetic radiation has the greatest energy?.................................
a) radio waves, approximately 10 m
b) infrared radiation, approximately 10 pm
c) UV radiation, approximately 200 nm
d) microwaves, approximately 10 mm
e) x-rays, approximately 100 pm
18. Give the ground state electro/configuration of the element
28
F and situate it in the
periodictable……………………………………………………………………………………
…………………………………………………………………………………………………
……………………………………………………………………..
19. How many electrons in an atom can have the same quantum number designated n=3, ml=
0,
ms=+
1
2
?I………………………………………………………………………………………
………………………………………
20. A sugar cube was heated until it melted completely. The heat was then increased, and the
sugar decomposed into a black solid mass. The changes associated with this process are:
a) A physical change for melting and a physical change for the decomposition.
b) A chemical change for the melting and a chemical change for the decomposition.
c) No change for the melting and a chemical change for the decomposition.?
d) A chemical change for the melting and a physical change for the decomposition.
e) A physical change for the melting and a chemical change for the decomposition
21. Which one of the following molecular formulas is also an empirical formula?...............
a) C
6
H
6
O
2
; b) C
2
H
6
SO c) H2Q2; d) H2P4O6; e) None of the above, since only ionic
compounds have empirical formulas.
22. Give the correct molecular orbital diagram of the ground state for the nitrogen molecule
given
7
N. ………………………………………………………………………………..
23. Which of the following statements about quantum theory is incorpdct? . a) Electrons
reside only in quantized energy levels
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