Download 1 Chemistry 1000 A Fall 2004 Second assignment The Periodic

Chemistry 1000 A
Fall 2004
Second assignment
The Periodic Table and Classes of Chemical Compounds
Responsible sections of Oxtoby, 4th edition: Chapter 3, Sections 3.1 – 3.4; 3.6; 3.8 (NB: the “missed” sections will be
covered later in the course)
Self-Study Assignment
Review Questions
Learn the names and symbols of the elements up to 36Kr.
Learn the SI prefixes (appendix B.3 in Oxtoby)
Learn the properties of the elements and their periodic classification as described in class.
Describe the key features of ionic compounds. Organize ionic compounds by location of constituent elements on the PT.
Describe the key features of molecular compounds. Organize the hydrides of the elements by their PT location.
Describe the key features of coordination complexes.
Study Questions from the end of Chapter 3
a) From the main section of Problems, do the relevant problems: 1-24; 49-56; 71-76. Also do 105-107 on coordination
complexes.
b) From the Additional Problems the relevant problems are 77-83; 85-86; 103-104
c) Detailed worked answers to all the odd-numbered problems are provided in the optional Student Solutions Manual. I
highly recommend that you obtain and use this resource if you find that you are not getting the right answer to a
significant number of the regular problems (a), or cannot immediately see where you went wrong. This is a judgment
that each student must make for themselves.
Problem Set #2
1. Which of the following molecules contains more O atoms per molecule? More atoms of all kinds? (a) sucrose, C12H22O11, or (b)
glutathione, C10H17N3O6S (the major, low-molecular-weight, sulfur-containing compound in plant or animal cells).
2. Give the total number of atoms of each element in one formula unit of each of the following compounds:
(a) CaC2O4
(d) Pt(NH3)2Cl2
(b) C6H5CHCH2 (c) Cu2CO3(OH) (e) K4Fe(CN)6
3. Write a molecular formula for the following two organic acids:
COOH
H2C COOH
H C OH
HO C COOH
CH3
lactic acid
H2C COOH
citric acid
4. Predict the charges on the ions formed by aluminum and selenium.
5. What charges are most commonly observed for ions of the following elements?
(a) Magnesium
(b) Zinc
(c) Iron
(d) Gallium
6. Give the symbol, including the correct charge, for each of the following ions:
(a) Strontium ion
(b) Aluminum ion
(c) Sulfide ion
(e) Titanium(IV) ion
(f ) Hydrogen carbonate ion (g) Perchlorate ion
(d) Cobalt(II) ion
(h) Ammonium ion
7. For each of the following compounds, give the formula, charge, and number of each ion that makes up the compound:
(a) K2S
(b) NiSO4
(c) (NH4)3PO4
(d) Ca(ClO)2
(e) KMnO4
8. Cobalt is a transition metal and so can form ions with at least two different charges. Write the formulas for the compounds formed with
the oxide ions and each of two different cobalt ions.
9. Which of the following are correct formulas for compounds? For those that are not, give the correct formula.
(a) AlCl
(b) NaF2
(c) Ga2O3
(d) MgS
10. Solid magnesium oxide melts at 2800˚C. This property, combined with the fact that it is not an electric conductor, makes it an ideal
heat insulator for electric wires in cooking ovens and toasters. In contrast, solid NaCl melts at the relatively low temperature of 801˚C.
What is the formula of magnesium oxide? Suggest a reason for its melting temperature being so much higher than that of NaCl.
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11. Name each of the following ionic compounds:
(a) K2S
(b) NiSO4
(c) (NH4)3PO4
(d) Ca(ClO)2
12. Write the formulas for all the compounds that can be made by combining each of the cations with each of the anions listed here. Name
each compound formed.
Cations
Anions
K+
CO32–
Ba2+
Br–
NH4+
NO3–
13. Give the name for each of the following binary, nonmetal compounds:
(a) NF3
(b) HI
(c) BBr3
(d) C6H14
14. Give the formula for each of the following nonmetal compounds:
(a) Butane
(b) Dinitrogen pentoxide
(c) Nonane
(d) Silicon tetrachloride
(e) Diboron trioxide (commonly called boric oxide)
15. Give the formula for each of the following ionic compounds:
(a) Ammonium carbonate
(b) Calcium iodide
(d) Aluminum phosphate
(e) Silver(I) acetate
(c) Copper(II) bromide
16. Which of the following pairs of elements are likely to form ionic compounds when they react with one another? Write appropriate
formulas for the ionic compounds you expect to form, and give the name of each.
(a) Chlorine and bromine
(b) Lithium and tellurium
(c) Sodium and argon
(d) Magnesium and fluorine
(e) Nitrogen and bromine
(f ) Indium and sulfur
(g) Selenium and bromine
17. Write the formula for each of the following compounds, and tell which ones are best described as ionic:
(a) Sodium hypochlorite
(b) Aluminum perchlorate
(c) Potassium permanganate
(d) Potassium dihydrogen phosphate (e) Chlorine trifluoride
(f ) Boron tribromide
(g) Calcium acetate
(h) Ammonium sulfite
(i) Disulfur dichloride
(j) Phosphorus trifluoride
18. Draw diagrams in the boxes shown here to indicate the arrangement of submicroscopic particles of each substance. Consider each box
to hold a very tiny portion of each substance. Each drawing should contain at least 16 particles, and it need not be three-dimensional.
19. How many elements occur in Group 4A of the periodic table? Give the name and symbol of each of these elements. Tell whether each
is a metal, nonmetal, or metalloid.
20. How many elements occur in the fourth period of the periodic table? Give the name and symbol of each of these elements. Tell if each
is a metal, nonmetal, or metalloid.
21. Which period in the periodic table is as yet incomplete? What is the name given to the majority of these elements and what well-known
property characterizes them?
22. How many periods of the periodic table have 8 elements, how many have 18 elements, and how many have 32 elements?
23. Write the coordination complex found in FeCl2.6H2O. Use the “square brackets” notation as done in the Lectures.
24. Write a formula for the coordination complex in which one chromium(III) ion is bonded to six ammonia molecules. What is the charge
on the complex? If the charge is neutralized with sulfate ions, write a formula for the complex salt.
25. Write a formula for the coordination complex in which a cromium(III) ion is bonded to six cyanide anions (CN–). With reference to
problem 24, write the formula for the salt that forms when the complex cation from problem 24 is used to neutralize it.
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Fun Question – A Periodic Table Crossword Puzzle: In the 2 , 2 crossword shown here, each letter must be correct four ways:
horizontally, vertically, diagonally, and by itself. Instead of words, use symbols of elements.
When the puzzle is complete, the four spaces will contain the overlapping symbols of 10 elements. There is only one correct solution.
Horizontal
1–2: Two-letter symbol for a metal used in ancient times
3–4: Two-letter symbol for a metal that burns in air and is found in Group 5A
Vertical
1–3: Two-letter symbol for a metalloid
2–4: Two-letter symbol for a metal used in U.S. coins
Single squares: All one-letter symbols
1. A colorful nonmetal
2. Colorless gaseous nonmetal
3. An element that makes fireworks green
4. An element that has medicinal uses
Diagonal
1–4: Two-letter symbol for an element used in electronics
2–3: Two-letter symbol for a metal used with Zr to make wires for superconducting magnets
This puzzle first appeared in Chemical and Engineering News, Dec. 14, 1987 (p. 86) (submitted by S. J. Cyvin) and in Chem Matters,
October, 1988.
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