Download KEY - Unit 6a - Practice Questions

Unit 6a Question Packet
Chemical Formulas & Equations
Name …………………KEY………………………
Period ………….
SKILLS
1. NAMES TO FORMULAS
2. FORMULAS TO NAMES
3. identifying MOLECULAR & EMPIRICAL FORMULAS
4. BALANCING EQUATIONS
5. applying the LAW OF CONSERVATION OF MASS
6. identifying TYPES OF REACTIONS
SKILL #1:
NAMES TO FORMULAS
– refer to your notes & RB p. 75-78
1. Complete the table for the following IONIC substances.
Name
Criss-Cross,
Formula
Electron-dot diagram
Reduce
+1
potassium fluoride
–1
K
+1
lithium bromide
Li
–1
Sr
barium iodide
gallium nitride
LiBr
Br
+2
strontium chloride
KF
F
–1
Cl
+2
–1
Ba
I
+3
–3
Ga N
+2
zinc sulfide
–2
Zn
SrCl2
BaI2
GaN
ZnS
S
2. How many elements are in each ionic compound in #1? How are they named?
They all contain two elements only.
Metal: always first (element name)
Nonmetal: element root w/ -ide ending
3. Write formulas for the following IONIC substances. Use Table E.
Criss-Cross,
Criss-Cross,
Name
Formula
Name
Reduce
Reduce
+1
–2
sodium sulfate
Na (SO4)
aluminum
chromate
Al (CrO4)
magnesium
hydrogen
carbonate
+3
+2
Mg (HCO3)
+1
Li (MnO4)
rubidium
oxalate
Rb (C2O4)
+1
Ba (PO4)
Al2(CrO4)3
calcium
hydroxide
Ca (OH)
Mg(HCO3)2
potassium
hydrogen
sulfate
–1
lithium
permanganate
–3
barium
phosphate
–2
–1
+2
Na2SO4
–2
LiMnO4
Rb2C2O4
ammonium
chloride
sodium
acetate
+2
Ba3(PO4)2
–1
+1
Ca(OH)2
–1
KHSO4
K (HSO4)
+1
–1
NH4Cl
(NH4) Cl
+1
Formula
–1
Na (C2H3O2)
NaC2H3O2
4. What do the ionic compounds in #3 all have in common? How are they named?
They all contain polyatomic ions.
+ ion: always first (element name or ammonium)
- ion: second (name on Table E)
5. What two types of bonds are found in all the compounds in #3? ionic & covalent
6. Write formulas for the following ionic substances. Use Table E if needed.
Criss-Cross,
Criss-Cross,
Name
Formula
Name
Reduce
Reduce
+2 –1
+3
–2
lead(II)
manganese(III)
PbI2
Mn
O
Pb
I
iodide
oxide
+1
–1
+2
–1
copper(I)
copper(II)
CuNO3
Cu
(NO
)
Cu
(NO
)
3
3
nitrate
nitrate
+3
–2
+3
–2
iron(III)
gold(III)
Fe
2(SO4)3
Fe (SO4)
Au O
sulfate
oxide
Formula
Mn2O3
Cu(NO3)2
Au2O3
+5
–1
+4
–3
chromium(V)
titanium(IV)
CrCl
Ti3P4
5
Cr Cl
Ti P
chloride
phosphide
+2
–2
+2
–1
platinum(II)
iron(II)
PtO
Fe(OH)2
Pt
O
Fe
(OH)
oxide
hydroxide
7. What do the ionic compounds in #6 all have in common? How are they named?
They all contain metals w/ more than 1 possible charge (oxidation state).
+ ion: always first (element name or ammonium
Charge of metal ion goes as Roman numeral in ( )
- ion: second (name on Table E or root / ide ending)
8. Write formulas for the following molecular substances. Underline the Greek prefixes in the
name.
Name
Formula
Name
Formula
dinitrogen trioxide
N2O3
silicon tetrafluoride
SiF4
diphosphorus pentoxide
P2O5
carbon tetrachloride
sulfur dioxide
SO2
boron triiodide
BI3
silicon dioxide
SiO2
carbon disulfide
CS2
xenon pentafluoride
XeF5
phosphorus pentabromide
PBr5
dihydrogen monoxide
H2O
boron trihydride
BH3
CCl4
SKILL #2:
FORMULAS TO NAMES
– refer to your notes & RB p. 75-78
9. Write IUPAC names for the following molecular substances.
Name
Formula
Name
Formula
dinitrogen pentoxide
N2O5
dihydrogen monosulfide
H2S
sulfur pentafluoride
SF5
boron trifluoride
BF3
phosphorus tribromide
PBr3
phosphorus trihydride
PH3
sulfur trioxide
SO3
dihydrogen monoxide (water)
H2O
diboron tetrahydride
B2H4
chlorine
Cl2
10. Write IUPAC names the following ionic compounds.
Formula
How MANY
oxidation
states listed for
the Metal?
One
Two or
more*
Name
Show work here:
LiBr
X
lithium bromide
Ag2O
X
silver oxide
X
SnO
tin(II) oxide
Ba3N2
X
barium nitride
AgBr
X
silver bromide
X
Cu3P
Mg(NO3)2
SnO
+1 –3
Cu3P
magnesium nitrate
X
NaNO3
sodium nitrate
KI
X
potassium iodide
NaClO
X
sodium hypochlorite
Fe(OH)3
X
iron(III) hydroxide
PbSO4
X
lead(II) sulfate
X
+3 –2
cobalt(III) oxide
X
NaHCO3
+2 –2
copper(I) phosphide
X
Co2O3
*Use charge of
NONmetal to figure
out charge of metal
Co2O3
+3
Fe(OH)3
+2
sodium hydrogen carbonate
Ni2(SO4)3
X
nickel(III) sulfate
Ti2O3
X
titanium(III) oxide
Al2(SO3)3
X
aluminum sulfite
Al(CN)3
X
aluminum cyanide
NH4Cl
X
ammonium chloride
KNO3
X
potassium nitrate
CaCO3
X
calcium carbonate
(NH4)2CO3
X
ammonium carbonate
NaS2O3
X
sodium thiosulfate
YBr3
X
yttrium bromide
–1
–2
Pb(SO4)
+3
–2
Ni2(SO4)3
+3
–2
Ti2O3
11. Write the formulas of the ionic compounds in #11 that have BOTH ionic and covalent
bonds. Circle the polyatomic ion in each formula.
Mg(NO3)2
NaNO3
NaClO
Fe(OH)3
PbSO4
NaHCO3
Ni2(SO4)3
Al2(SO3)3
Al(CN)3
NH4Cl
KNO3
CaCO3
(NH4)2CO3
NaS2O3
SKILL #3:
– refer to your notes & RB p. 74
identifying MOLECULAR & EMPIRICAL FORMULAS
12. Below are a list of formulas. Write the empirical formula (if not already empirical) and
identify the type of substance & type of bonds inside the substance.
Type of
Empirical
Type of Bonds
Electrons are…
Substance
Formula
formula
(ionic and/or
(shared and/or
(ionic or
(simplest ratio)
covalent)
transferred)
covalent)
a.
C4H10
C2H5
covalent
covalent
shared
b.
C3H6
CH2
covalent
covalent
shared
c.
N2O4
NO2
covalent
covalent
shared
Na2SO4
Already
empirical (ionic)
ionic
BOTH
BOTH
C6H10
C3H5
covalent
covalent
shared
ionic
ionic
transferred
ionic
BOTH
BOTH
d.
e.
f.
g.
h.
Al2O3
NH4NO3
Already
empirical (ionic)
Already
empirical (ionic)
C11H22O11
CH2O
covalent
covalent
shared
K2S2O3
Already
empirical (ionic)
ionic
BOTH
BOTH
j.
S2O4
SO2
covalent
covalent
shared
k.
CH4
CH4
covalent
covalent
shared
l.
C6H12Cl2O2
C3H6ClO
covalent
covalent
shared
i.
SKILL #4:
– refer to your notes & RB p. 79, 81
BALANCING EQUATIONS
13. Balance the following equations using the smallest, whole-number coefficients.
a.
__3__Mg
*Start w/ O
+
____Mn2O3

__3__MgO
+
__2__Mn
b.
_____C6H12O6  ___2__C2H5OH + ___2__CO2
*Start w/ H
c.
_____C3H8 +
__5__ O2
 __4__ H2O
+ __3__ CO2
*start w/ C or H
d.
__2__FeCl3 + ____Be3(PO4)2
*Start w/ Be, Cl, or (PO4)

__3__BeCl2
+
__2__FePO4
e.
__4__NH3 +
*Start w/ H
__3__O2

__2__N2 +
__6__H2O
f.
__3__ C2H4O2 + ____ PCl3  __3__ C2H3OCl + ____ H3PO3
*start w/ Cl
*g.
_____Fe2O3 + __3___CO  __2__Fe + __3__CO2
* must start w/ O, want an EVEN # of O’s on both sides, so CO
gets a 3 in front
14. Given the following incomplete equations, write the formula of the molecule represented
by X.
a.
X + Cl2  C2H5Cl + HCl
b.
4Fe + 3O2  2X
C2H6
Fe2O3
15. Which equation represents conservation of mass?
(1) H2 + Cl2  HCl
(2) H2 + Cl2 2HCl
(3) H2 + O2  H2O
SKILL #5:
(4) H2 + O2  2H2O
– refer to your notes & RB p. 81
applying the LAW OF CONSERVATION OF MASS
16. Given the reaction:
2H2 + O2  2H2O
What is the total mass of water formed when 8 grams of hydrogen reacts completely
with 64 grams of oxygen?
8 g + 64 g = X
72 g = X
17. When glucose is fermented, it produces ethanol and carbon dioxide. If 60.0 grams of
glucose is fermented and produces 16.5 grams of carbon dioxide gas, what mass of
ethanol is produced?
Glucose  ethanol + CO2
60 g =
X + 16.5 g
43.5 g =
X
18. A 4.86-gram sample of calcium reacted completely with oxygen to form 6.80 grams of
calcium oxide. This reaction is represented by the balanced equation below.
2Ca(s) + O2(g)  2CaO(s)
Determine the total mass of oxygen that reacted.
4.86 g + X
= 6.80 g
X
= 1.94 g
SKILL # 6:
– refer to your notes & RB p. 80
identifying TYPES OF REACTIONS
19. Complete the table below. The first one is done for you.
Equation
Reactant(s)
Product(s)
Type of Reaction
a.
Cl2 + 2NaI  2NaCl + I2
Cl2 and NaI
NaCl and I2
Single replacement
b.
HNO3 + LiOH  H2O + LiNO3
HNO3 + LiOH
H2O + LiNO3
Double replacement
c.
2NaN3  2Na + 3N2
NaN3
Na + N2
decomposition
d.
Ba(NO3)2 + K2SO4 
2KNO3 + BaSO4
Ba(NO3)2 +
K2SO4
KNO3 + BaSO4
Double replacement
e.
BaO + SO3  BaSO4
BaO + SO3
BaSO4
synthesis
f.
2Al + Fe2O3  Al2O3 + 2Fe
Al + Fe2O3
Al2O3 + Fe
Single replacement
g.
P4 + 6Cl2  4PCl3
P4 + Cl2
PCl3
synthesis