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Assignment # 6
Lab (/25)
1. Titration Lab: Write the following:
 Purpose: 2-3 sentences stating why we performed this lab
 Observations: hand in completed lab data sheet
 Sample calculations: for calculations done, do 1 sample calculation to show how values were determined
 Conclusion: In a paragraph, discuss the following:
o Lab A-1: % purity you found of the KOH and discuss why the purity of a “tech grade” substance
may not be 100%
o Lab A-2: compare mass content you found in tablets with the value identified on the label
o Lab A-3: state molar mass and identity of salt you used. Compare with real molar mass & identity.
o Lab A-4: Compare your 2 answers. Which do you think is more accurate? Why?
o Lab A-5: state molar mass and identity of the carbonate you used. Compare with real molar mass &
identity.
o Lab A-6: State % ammonia found in commercial cleaner. Compare with value found on container.
o State any errors or improvements to future labs!
2. Assign Oxidation numbers to the elements in bold print. Answer on this page! (/25)
a) Mg
b) P4
c) Cl
f) Na2O
g) Fe2O3
k) SO2
l) PCl5
p) CO3
–
d) HCl
e) CaO
h) N2O3
i) P2O3
j) PF3
m) ThO2
n) CO2
o) CO
–
2–
q) Ca(VO3)2 r) ClO
u) K2CrO4
v) Na2Cr2O7 w) SO3
s) NaClO2 t) KClO3
2–
x) NO
y) NO2
3. Balance the following eq'ns taking place using oxidation #'s. Put final answer on this page! Attach work on
a separate page. (3 marks each = /30)
a) MnO4
–
2–
b) Cr2O7
c) SO4
2–
2+
+
2+
+
H

Mn
Fe
+
H
+

Cr
Cu
+
H
+

Cu

Fe
+
Fe
+
+
2+
3+
d) H2SO3
+
Fe
+
H2O
e) KMnO4
+
HCl

KCl
3+
2+
2+
+
3+
+
Fe
+
Fe
+
H2O
+
SO2
+
H2O
+
SO4
+
H
Cl2
+
MnCl2
3+
+
2–
+
H2O
+
H2O
f) CaC2O4 +
g) I2
+
KMnO4 +
H2SO4

HIO3
HNO3
h) K2Cr2O7
+
i) Sb2 (SO4) 3
j) KIO3

HCl
+
KMnO4
+
KI +

+
NO2
KCl
+
H2 O 
+
HCl
CaSO4

+
+
CrCl3
+
MnSO4 +
H2O +
H2O
+
H3SbO4 +
KCl
K2SO4 +
Cl2
K2SO4 +
I2
+
+
H2O
MnSO4
+
H2SO4
H2O
4. Balance the following eq'ns taking place using half-reaction method. Put final answer on this page! Attach
work on a separate page. (5 marks 3ach = /20)

a) O3
+
I-
b) Pt
+
NO3-
c) CN
–
d) MnO4-
–
+
ClO2
+
I-
+
Cl
IO3-
+
–



–
CNO
I2
+
+
O2
PtCl6
Cl
2–
–
Mn+2+
+
NO2
CO2