Pre AP Compound Practice Exam 2013
Complete the following free response questions.
1.
List four properties of ionic compounds:
hard, brittle, high melting point,
nonconductor, crystalline solid at room temp.
2. How can you identify a binary molecular compound from the name/formula? 2
nonmetals, prefixes
3. Why is it important to use roman numerals like II or IV when naming an ionic compound with a transition metal?
To know the charge for the formula
4. Describe the actions of the valance electrons in metallic bonds. Free floating sea of electrons
5. List three properties of metals that is a direct result of metallic bonding.
Shiny, conductor,
malleable and ductile
6. In a molecular bond, electrons are
shared
while in an ionic bond electrons are _lost_ or _gained_.
7. Non-metals tend to _gain_ electrons and become _anions (negative
ions)_ in ionic bonding.
8. Atoms want a full outer energy level. For most atoms, this is _8_ electrons which is why this is called the
_octet_ rule.
9. Give the molar mass for the following compounds.
a. H2SO4
b. C2H2
c. Ba(OH)2
a) 2H(1.0g) + 1S(32.1g) + 4O(16.0)= 98.1 g H2SO4
b) 2C (12.0g) + 2H (1.0g) = 26.0 g C2H2
c) 1Ba (137 g) + 2O (16 g) + 2H (1.0 g)= 171 g Ba(OH)2
10. Draw an electron dot diagram to predict the type of bonding and the number of
bonds between two atoms of nitrogen in the diatomic molecule N2.
:N=N: covalent triple bonds
11. Name the following compounds:
1. Li2S
lithium sulfide
6. N7S8
heptanitrogen octasulfide
2. CO3
carbon trioxide
7. PbO
lead(II) oxide
3. CuBr
copper(I) bromide
4. Cu2O copper
5.
Na2SO4
(I) oxide
8. FeBr3
Iron(III) bromide
9. Ba(CN)2
Barium cyanide
sodium sulfate
12. Write the formulas for the following compounds:
6. lithium carbonate
7. potassium cyanide
Li2CO3
KCN
5. cupric sulfate
CuSO4
6. dihydrogen monoxide
H2O
8. tin (IV) chlorite
Sn(ClO2)4
7. Lead (II) iodide
PbI2
9. beryllium oxide
BeO
8. ammonium sulfate
(NH4)2SO4
13. What is meant by the term polar? How can you tell if a bond it polar covalent, nonpolar covalent or ionic?
Means has electric poles (+ or negative ends), bond polarity by
electronegativity differences of atoms (ionic >1.81, nonpolar covalent <0.41,
Polar covalent between these
14. Calculate the mass of
1.25 moles of LiCl(42.4 g LiCl/1 mol LiCl)= 53.0 g LiCl
2.57 x 1023 molecules of H2O (18.0 g H2O/6.02 X 1023 Molecules)= 7.68 g H2O
15. Find the % oxygen by mass in water.
% O = 16 g O/18 g H2O X 100%
2H (1.0 g) + 1O (16 g) = 18 g H2O
= 88.9% O
16. If a compound consists of 38.7 % C, 16.1 % H and 45.2 % N, what is the empirical formula?
38.7 g C (1 mol C/ 12 g C) = 3.225 mol C
C 3.225/3.225
16.1 g H (1 mol H/ 1 g H) = 16.1 mol H
H 16.1/3.225
1 mol N
45.2 g N (
/ 14 g N) = 3.229 mol N
N3.2259/3.225
C H5N
Complete the following multiple choice questions by choosing the best answer.
17. There are _____ paired and _____ unpaired electrons in the Lewis symbol for a phosphorus atom.
2 paired (1 pair) and 3 unpaired
18.
Based on the octet rule, magnesium most likely forms a _____ ion.
a. Mg2+
19.
Which ion below has a noble gas electron configuration?
b. Be2+
20.
Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration?
O Sr Na Se Br
d. O & Se
21.
Elements from opposite sides of the periodic table tend to form ____________.
b. ionic compounds
22.
How many single covalent bonds must a silicon atom form to have a complete octet in its valence shell?
b. 4
23.
Compounds consisting entirely of nonmetals ____________.
d. are molecular
24.
A double bond consists of _____ pairs of electrons shared between two atoms.
b. 2
25.
What is the maximum number of double bonds that a hydrogen atom can form?
a. 0
26.
The central atom in _____ violates the octet rule.
a. ClF3
27.
The Lewis structure of the CO2 molecule has ____ double bond(s).
c. 2
28.
The basis of the VSEPR model of molecular bonding is ____________.
d. electron pairs in the valence shell of an atom will arrange themselves so
as to minimize repulsions
29.
The electron-domain geometry of _____ is tetrahedral.
a. CBr4 (tetrahedral)
b. PH3 (trigonal pyramidal—from tetrahedral)
c. CCl2Br2 (tetrahedral)
d. XeF4 (exception to octet rule—square planar)
e. all of these except XeF4
30.
The molecular geometry of the SF2 molecule is __________.
b. bent
Fill in the missing name or formula:
Name
Formula
calcium chloride
________CaCl2_____________
barium nitride
______Ba3 N2______________
silver oxide
____Ag2O_____________
iron(II) oxide
_____FeO______________
lithium sulfate
______Li2SO4____________
barium nitrate
______Ba(NO3)2_________
dinitrogen pentoxide
_______N2O5_________
calcium acetate
______Ca(C2H3O2)2_____
water
______H2O______
ammonia
_______NH3________
magnesium sulfate
______MgSO4__________
___calcium phosphide_________
Ca3P2
__carbon tetrabromide__________ CBr4
__potassium chloride_________
KCl
_____sodium carbonate______
Na2CO3
_____aluminum oxide _________
Al2O3
_____iron (II) bromide_________
FeBr2
_____Tin (IV) chlorate______
Sn(ClO3)4
_____nitrogen dioxide_______
NO2
______silver bromide_______
AgBr
________sodium nitrate_______
NaNO3
______copper (II) chloride____
CuCl2
Find the molar mass of the following compounds:
lithium sulfate Li2SO4 2 Li(6.94g)+ 1 S(32.1g) + 4O(16g)=109.98g
barium hydroxide
Ba(OH)2 Ba (137g)+ 2O(16g)+ 2H(1 g)= 171 g
magnesium acetate
Mg(C2H3O2)2 1 Mg(24.3g)+ 4C(12g)+6H(1g)+ 4 O(16g)= 142.3 g