HCCS CHEM 1405 PRACTICE EXAM II: 5th, 6th & 7th editions of Corwin’s Introductory
Chemistry textbook
Multiple Choices: Choose the best answer. The best answer is shown in bold.
1. Which of the following is not part of Dalton’s theory?
(A) An element is composed of tiny, indivisible, indestructible particles called
atoms.
(B) All atoms of an element are identical and have the same properties.
(C) Atoms of different elements combine to form compounds.
(D) Compounds contain atoms in small fractional number ratios.
(E) Atoms can combine in more than one ratio to form different compounds.
Hint: For 7th ed., see section 4.1: p. 101; for both 5th ed. and 6th ed., see Section
5.1.
2. How many protons, neutrons, and electrons are there in 107Ag?
(A) 47, 107, 60
(B) 107, 47, 60
(C) 47, 60, 47
(D) 60, 47, 47
(E) 60, 107, 47
Hint: For 7th ed., see section 4.4, p. 107; for both 5th ed. and 6th ed. Section 5.4.
3. Which of the following is correct concerning isotopes?
(A) Isotopes of the same element have a different number of protons in the
nucleus.
(B) Isotopes of the same element have a different number of electrons in the
nucleus.
(C) Isotopes of the same element have a different number of neutrons in the
nucleus.
(D) Isotopes of the same element have same mass numbers.
(E) Isotopes of the same element have same atomic notations.
Hint: For 7th ed., see section 4.4, p. 105; for both 5th ed. and 6th ed. Section 5.4.
4 Assuming that there are only two naturally occurring isotopes for silver: 107Ag
(amu 106.91) and 109Ag (amu 108.90). The mass percentage of the former is
51.840% and the latter 48.16%, respectively. What is the atomic mass (or called
average atomic mass; it’s the number with decimals found in the periodic table)
of this mixture?
(A) 107.87 amu
(B) 374.55 amu
(C) 207.43 amu
(D) 44.69 amu
(E) 122.12 amu
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Hint: For 7th ed., see section 4.5, p.p. 108-109; for both 5th ed. and 6th ed., see
Section: 5.5. This is a very important question and you must convert the % into
decimals first and then apply the formula and memorize it:
M = M1X1 + M2X2 = 106.91x0.51840 + 108.90x0.4816 = 107.87
For three isotopes: Example Exercise 4.3 in 7th ed., and Example Exercise 5.3 in
5th & 6th ed.: 28Si (27.977 amu; 92.21% abundance), 29Si (28.976 amu; 4.70%
abundance) and 30Si (29.974 amu; 3.09% abundance). The atomic mass M = M1X1
+ M2X2 + M3X3 = 27.977x0.9221 + 28.976x0.0470 + 29.974x0.0309 = 28.09 amu
by rounding to two decimals.
5. Which of the following statement is correct?
(A) The wavelength of blue light is in the ultra-violet (UV) range.
(B) The frequency of the red light is higher than the green light’s.
(C) The energy of X-ray is higher than the microwave’s.
(D) Infrared belongs to visible light.
(E) The higher the frequency the lower the energy for electromagnetic waves.
Hint: For 7th ed., see section 4.6, Figure 4.8; for both 5th ed. and 6th ed., see
Section 5.6.
6. Which of the following energy level changes for an electron is most energetic?
(A) 6 → 1
(B) 5 → 1
(C) 4 → 1
(D) 3 → 1
(E) 2 → 1
Hint: For 7th ed., see section 4.6, Figure 4.13; for both 5th ed. and 6th ed., see
Section 5.8, Figure 5.13.
7. Which of the following statement is correct?
(A) For energy level 2, there are 2s, 2 p, and 2d energy sublevels.
(B) There are maximum 2 electrons in the energy sublevel 3p.
(C) For energy level 4, there are 4s, 4p, 4d, and 4f energy sublevels.
(D) There are maximum 6 electrons in the energy sublevel 4d.
(E) There are maximum 18 electrons in energy level 4.
Hint: For 7th ed., see section 4.9, Table 4.3; for both 5th ed. and 6th ed., see
Section 5.9.
8. Which of the following is a correct order of the energy sublevel?
(A) p, d, s, f
(B) s, p, d, f
(C) f, d, p, s
(D) f, s, d, p
(E) s, d, f, p
2
Hint: For 7th ed., see section 4.9, Table 4.3; for both 5th ed. and 6th ed., see
Section 5.9.
9. Which of the following is correct electron configuration for silicon (atomic
number 14)?
(A) 1s22s22p63s23p2
(B) 1s22s22p63s23p63d64s24p5
(C) 1s22s22p63s23p63d104s24p5 (arranged according to the order of principle
quantum number)
or 1s22s22p63s23p64s23d104p5 (arranged according to the order of orbital
energy)
(D) 1s22s22p63s23p63d64s24p1 (arranged according to the order of principle
quantum number)
or 1s22s22p63s23p64s23d64p1 (arranged according to the order of principle
quantum number)
(E) 1s22s22p63s23p6
Hint: For 7th ed., see section 4.10 & memorizing the energy sublevel (i.e. orbital
energy) of Figure 4.16. There is an easier way to memorize it shown below. For
both 5th ed. and 6th ed., see Section 5.10 or Figure 5.16. This is a very important
question. Follow the definition and energy order of energy sublevel (sometimes,
it’s called as orbital) in the textbook. For the one shown below, the electrons
filled-in order is from the upper right corner to left bottom corner starting the
first row and follow the same procedure for the second, third, etc. rows.
A different way to present the Figure 5.16 is as following: (going from upper
right corner to the bottom left corner for energy order):
1s
2s
2p
3s
3p
3d
4s
4p
4d
4f
10. Which of the following element corresponds to the electron configuration,
1s22s22p63s23p63d64s2?
(A) Ar
(B) Sc
(C) Fe
(D) Cu
(E) Ca
Hint: Atom, element, molecule, and compound are all electrically neutral which
means carrying no charges. For 7th ed., see section 4.10 or section 5.6, especially
Example Exercise 4.10 and Example Exercise 5.7; for both 5th ed. and 6th ed., see
Section 5.10 or section 6.6.
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11. Which of the following statement is correct?
(A) The IUPAC convention uses IA– VIIIA while American convention uses 1–18.
(B) Mn is the inner transition element while Mg is the representative element.
(C) F has the smallest atomic size in the Group VIA.
(D) Fr has the smallest size in the Group IA.
(E) The atomic size of Ar is smaller than Na.
Hint: For 7th ed., see sections 5.2 to 5.4; for both 5th ed. and 6th ed., see Sections
6.2 to 6.4.
12. Which of the following statement is correct?
(A) U belongs to the inner transition d-block elements.
(B) Ca belongs to the transition d-block elements.
(C) Al belongs to the representative s-block elements.
(D) Mg belongs to the representative s-block elements.
(E) B is a nonmetal.
Hint: For 7th ed., see sections 5.2 to 5.6 (blocks of elements); for both 5th ed. and
6th ed., see Sections 6.4 to 6.6.
13. Which of the following statement is correct?
(A) The product formed when metallic sodium reacted to chlorine gas is KCl.
(B) The chemical formula for the oxide of barium is BaO.
(C) The highest energy sublevel for U is 4f sublevel.
(D) There are three valence electrons for N.
(E) Ne has the most metallic character in the period 2.
Hint: For 7th ed., see sections 5.4 to 5.7 See both 5th ed. and 6th ed. Sections 6.5
to 6.7.
14. Draw the electron dot formula for an atom of strontium (Sr).
Hint: For 7th ed., see section 5.8; for both 5th ed. and 6th ed., see Section 6.8.
Need to find out the number of valence electrons. The number of valence
electrons is same as the group number in Roman number.
15. Which of the following groups of elements has the highest ionization energy?
(A) Group IA (B) Group IIA (C) Group IIB (D) Group VIIA (E) Group VIIIA
Hint: For 7th ed., see section 5.9; for both 5th ed. and 6th ed., see section 6.9.
16. Which of the following statement is wrong?
(A) S2 is isoelectronic with Ar.
(B) The charge of oxide ion is -1.
(C) The charge of aluminum ion is +3.
(D) The charge of hydrogen ion is +1.
+
(E) Ca2 is isoelectronic with Cl 1.
Hint: For 7th ed., see section 5.10; for 5th ed. and 6th ed., see Section 6.9.
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17. Which of the following statement is wrong?
(A) Helium has the highest ionization energy among all elements in the periodic
table.
(B) The alkali metals have the lowest ionization energy while the noble gases
have the highest ionization energy.
+
(C) The electronic configuration of Mn2 is 1s22s22p63s23p64s23d3.
(D) The electron configuration for Cl is 1s22s22p63s23p6.
(E) The electronic configuration of Mn is 1s22s22p63s23p64s23d5.
Hint: For 7th ed., see Section 5.10: electron configuration of ions—p. p. 151-152;
See both 5th ed. and 6th ed. Section 6.10. Need to match the total electron
number with the atom or ionic symbol. For an atom, the number of electron is
same as the atomic number (i.e. number of protons). For cation, subtract the
number of positive charge; for anion, add the number of negative charge.
18. Which of the following statement is correct?
+
(A) Na is a polyatomic ion.
(B) PO43 is a polyatomic anion.
(C) When a compound is dissolved in water, it is called a non-aqueous solution.
(D) HNO3 is a binary acid.
(E) CaO is a molecular compound.
Hint: For 7th ed., see section 6.1 and Example Exercises; for both 5th and 6th ed.,
see Section 7.1. Please read the explanation in the Example Exercises.
19. Which of the following pairs is correct?
+
(A) Ammonia, NH4
+
(B) Manganese ion, Mg2
+
(C) Iron (II) ion, Fe3
(D) Hydride, OH
(E) Permanganate ion, MnO4
Hint: For 7th ed., see sections 6.2 and 6.3; for both 5th ed. and 6th ed., see
Sections 7.2 and 7.3. Remember that naming the transition metal ion we must
specify the charge with Roman number. Hydride is H .
20. Which of the following chemical formulas is correct?
(A) The chemical formula formed by manganese (II) ion and phosphate ion is
Mn3PO42
(B) The chemical formula formed by sodium ion and chloride ion is Na1Cl1.
(C) The chemical formula formed by manganese (II) ion and phosphate ion is
Mn3 (PO4)2
(D) The chemical formula formed by mercury (II) ion and fluoride ion is HgF.
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(E) Copper (II) nitrate is also called cupric nitrate and its chemical formula is
Cu2NO3.
Hint: For 7th ed., see sections 6.4, 6.5 and 6.6. For 5th ed. and 6th ed., see Sections
7.4, 7.5 and 7.6 for naming ionic compounds. Writing the correct chemical
formulas is very important. You first need to know the formula for each ion and
then put them excluding the signs together by exchanging the charges if the
charges are different. If the charges are the same except the signs, then simply
put them together.
Like manganese (II) oxide: manganese has +2 charges and oxide has –2 charges
+
as Mn2 and O2 . Since the charges are the same except the signs, we simply put
them together as MnO
Like manganese (II) nitride: manganese has +2 charges and nitride has –3
+
charges as Mn2 and N3 . Since the charges are different, and thus we simply
exchange the charges excluding the signs and put them as subscripts as Mn 3N2
Like manganese (II) phosphate: manganese has +2 charges and phosphate has –3
+
charges as Mn2 and PO43 . Since the charges are different, and thus we simply
exchange the charges excluding the signs and put them as subscripts; be careful
that since phosphate has subscript in oxygen atom and to avoid confusion, we
must write is as Mn3(PO4)2 instead of Mn3PO42. Because the former indicates
there are two P atoms and 2x4=8 oxygen atoms, while the latter indicates there
is one P atom and there are 42 oxygen atoms.
Sodium chloride is NaCl; mercury (II) fluoride is HgF2; copper (II) nitrate is
Cu(NO3)2
21. Which of the following is not a molecular compound?
(A) KCl
(B) HF
(C) CCl4
(D) BF3
(E) H2CO3
th
th
th
Hint: For 7 ed., see sections 6.5 to 6.7; for 5 ed. and 6 ed., see Section 7.7,
7.8 and 7.9. This is the definition. Molecular compounds contain only
nonmetal atoms; while ionic compounds contain metal and nonmetal atoms.
+
The only exception is that compound that contains ammonium ion, NH4 , is
an ionic compound (see Hints in the explanation in the following example.
For example: NH4Cl
Which of the following formulas represents an ionic compound?
(A) NO
(B) HCl
(C) AsBr3
(D) MgO
(E) CO
Hint: For 7th ed., see sections 6.5 to 6.7; for both 5th ed. and 6th ed., see Sections
7.4 to 7.6 for naming ionic compounds and Sections 7.7 to 7.8 for naming the
molecular compounds and Sections 7.8 and 7.9 for naming acids. This is the
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definition. Ionic compound, composing cation(s) and anion(s), contains one or
more metal and nonmetal atoms; while molecular compounds contain all
nonmetal atoms. There is an exception for ionic compound: For any compounds
+
that contain NH4 are considered as ionic compound as they are the salts,
products of acid and base reaction. For example, NH4Cl, (NH4)2SO4, (NH4)3PO4 are
ionic compounds.
22. What is the correct name for BaHPO4?
(A) barium phosphate
(B) barium hydrogen phosphate
(C) barium dihydrogen phosphate
(D) monobarium hydrogen phosphate
(E) barium phosphoric acid
Hint: For 7th ed., see sections 6.6 to 6.9 (oxoacids); applications of Table 6.3; for
both 5th ed. and 6th ed., see Sections 7.6 and 7.9.; applications of table 7.5.
23. What is the correct name for N2O5?
(A) chromium (III) oxide
(B) dinitrogen pentoxide.
(C) nitrogen oxide
(D) nitric acid
(E) nitrogen (V) oxide
Hint: For 7th ed., see section 6.7; for both 5th ed. and 6th ed., see Section 7.7.
24. Which of the following pairs is correct?
(A) N2H4, dinitrogen trtrahydrogen
(B) Ca(NO3)2, calcium dinitrate.
(C) Ammonia, NH3
(D) C2H2, dicarbon hydride
(E) Sodium monohydrogen carbonate
Hint: Comprehensive: Naming from all sections.
25. Which of the following pair is wrong?
(A) The name for H2S as an acid is hydrosulfuric acid.
(B) The name for HCl as a gas is hydrogen chloride.
(C) The name for HC2H3O2 (or written as CH3COOH) is acetic acid or said vinegar.
(D) The name for H2CO3 is carbonic acid.
(E) The name for SF6 is monosulfur hexafluoride.
Hint: Comprehensive: Naming from all sections.
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