Chemistry 103
Assignment No. 7
Formula of ionic compounds
I.
Choose the symbol, including the correct charge, for each of the following ions:
Ion
Symbol
A. Chromium (III) ion 1. Cr+
II.
2. Ch+
3. Ch3+
5. Cr3+
B. Ammonium ion
1. NH4+ 2. NH2–
3. NH43+ 4. NH52+
5. NH2-
C. Phosphate ion
1. PO4+
2. PO3–
3. PO43+ 4. PO22–
5. PO43-
D. Sulfate ions
1. SO4+
2. SO3+
3. SO43– 4. SO42–
5. SO32-
E. Carbonate ion
1. CO4+
2. CO3+
3. CO43– 4. CO42–
5. CO32-
Choose each of the following compounds:
Formula
III.
4. Cr2+
Name
F. K2S
1. Potassium sulfate
3. Dipotassium monosulfate
2. Potassium sulfide
4. Dipotassium monosulfide
G. Al(OH)3
1. Aluminium hydride
3. Dialuminium hydride
2. Aluminium hydroxide
4. Dialuminium trihydroxide
H. CuCO3
1. Copper carbide
2. Copper carbonate
3. Copper monocarbidetrioxide 4. Copper carbide oxide
I. CaSO4
1. Calcium sulfate
2. Calcium sulfide
3. Calcium monosulfidetetraoxide 4. Calcium sulfide oxide
Choose the correct formula for each of the following compounds:
Name
Formula
J. Barium nitrate
1. Ba(NO3)2
4. BaN3
K. Iron(III) chloride
1. FeCl2
4. (Fe)2Cl
L. Lithium oxide
1. LiO3
4. (Li)O3
2. (Ba)2NO3
5. BaNO2
2. FeCl3
5. Fe3Cl
2. Li2O3
5. (Li)2O3
3. BaN2
6. Ba(NO2)2
3. FeCl
6. (Fe)3Cl
3. Li2O
6. (Li)2O
2
IV.
Identify the correct combination of ions present in the following compounds:
Ionic Compound
Cation/Anion
M. (NH4)2Cr2O7
1. NH4+ / Cr2O72–
3. (NH4+ + Cr3+) /O2–
2. (N2- + H+) / Cr2O72–
4. (N2- + H+ + Cr3+) /O2–
N. Fe2(CO3)3
1. Fe2+ / CO33–
3. Fe3+ / C– + O32–
2. Fe3+ / C2– + O32–
4. Fe3+ / CO32–
O. Al(OH)3
1. Al2+ / OH3–
3. (Al3+ + H+) / O2–
2. (Al2+ + H+) / O2–
4. Al3+ / OH–
PROBLEM QUESTION (wt = 5):
You can skip the unit for this question but to obtain full credit your
answer must have the correct significant digits.
P. You have a white crystalline solid, known to be one of the potassium compounds. To determine
which, you measure the solid’s density. You measure out 18.82 g and transfer it to a granulated
cylinder containing kerosene (in which salts will not dissolve). The level of liquid kerosene rises
from 8.5 mL to 15.3 mL. Calculate the density (in g/L) of the potassium compound.
ANSWER LIST – List your answers here before uploading on the computer in P-469. Check to
make sure they are correct.
Multiple choice:
No.
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Answer
Problem: __________________
Name: __________ ________
N
O