More
Practice
Questions!
1. Classify each of the following (unbalanced) reactions as redox, acid-base, precipitation, combustion, synthesis, and/or
decomposition (more than one may apply).
a.
H2SO4 (aq) + NaClO3 (aq) Na2SO4 (aq) + HClO3 (l)
b.
Na2SO4 (aq) + Ba(NO3)2 (aq)  BaSO4 (s) + NaNO3 (aq) PRECIPITATION
c.
Na (s) + H2O (l)  H2 (g) + NaOH (aq)
REDOX
d.
H2 (g) + O2 (g)  H2O (l)
SYNTHESIS and COMBUSTION
ACID-BASE
2. Write the chemical formula that corresponds to each of the following names:
a. Cobalt(II) nitrate
Co(NO3)2
b. Potassium sulfate
K2SO4
c. Sodium sulfide
Na2S
d. Dinitrogen pentoxide
N2O5
e. Iron(III) oxide
Fe2O3
f. Iron(II) hydroxide
Fe(OH)2
4. How many valence electrons does an atom of Astatine have? SEVEN
5. Draw a carbon triple bonded to a fluorine, then complete the octet of each atom. What would the charge on each be,
as drawn?
:CF:
C is -1 (has 5 that belong to it, normally 4), F is +2 (has 5, normally 7)
THIS IS AN INTENTIONALLY BAD STRUCTURE!
6. Balance the following reaction. What type of reaction is it?
CaCl2 (aq) + K2SO4 (aq) → 2KCl (aq) + CaSO4 (s)
PRECIPITATION
7. How many protons, neutrons, and electrons are there in an atom of 128I-?
53 PROTON, 75 NEUTRONS, 54 ELECTRONS
8. How many significant figures are there in the following measurements?
0.0530 m
(3)
3.40x102 kg
(3)
2700 mL
(2)
9. A student weighs out 45 g of CaCl2. How many moles of calcium chloride were weighed out? How many moles
of chloride? How many atoms of chloride?
0.405 moles CaCl2 = 0.810 moles Cl- = 4.87x1023 atoms Cl10. What is the formula of the compound formed from Al3+ and S2-? Is it ionic or covalent?
Al2S3. IONIC
11. 1.00 g of vanadium is burned, and the resulting vanadium oxide is found to weigh 1.785 g. Write a balanced reaction
equation for this process.
0.0196 moles V, 0.049 moles O
1:2.5 ratio (or 2:5) so
4V + 5O2  2V2O5