7/29/2019 jcaps.analtech2mid
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Technological University of the Philippines-Visayas
Talisay City, Negros Occidental
JUNIOR CHEMISTRY AND PHYSICS SOCIETY
ANALYTICAL TECHNIQUES II
Midterm Exam Review 2012
MULTIPLE CHOICE.
_____ 1. In the titration by the use of potassium permanganate,
permanganate ions are considered as-
a. oxidizing agent b. reducing agent c. catalyst
_____ 2. Endpoint is reached if the appearance of what color is
taken in permanganate process?
a. Pink b. yellow c. colorless_____ 3. Decomposition of
permanganate ions results to-
a. The formation of Mn+2 ions b. the formation of MnO2 c.
deterioration of MnO4-_____ 4. If the permanganate is taken with
arsenic (III) ions, arsenic (III) ions-
a. Oxidizes into As+5 ions b. produces H3AsO4 c. does not
participate in the reaction_____ 5. The equivalent weight of KMnO4
in the permanganate titration in acidic medium is the molar mass
of
KMnO4 divided by- a. 5 b. 1 c. 3
_____ 6. Which of the following methods in permanganate
titration will not cause errors in the analysis?
a. The permanganate solution is in contact with rubber.b. Boil
the solution before standardizing.c. The permanganate solution is
exposed in light.
_____ 7. Which of the following solutions is not oxidized with
air?
a. Permanganate b. arsenite c. ferrous solution_____ 8. Which of
the following is false about permanganate process?
a. If the titration is made slowly, back-titration with ferrous
sulfate should not be necessary.b. A permanganate endpoint is
always permanent.c. Permanganate will oxidize chloride ions in hot
solutions in the presence of iron salts.
_____ 9. Which of the following reactions is the main reaction
of Volhard method?
a. MnO4- + 2 H2O + 3 e- -----> MnO2(s) + 4 OH-b. 3 Mn+2 + 2
MnO4- + 4 OH- -------> 5 MnO2 + 2 H2Oc. MnO2 + C2O4- + 4 H+
-------> Mn+2 + 2 CO2 + H2O
_____ 10. It is a soluble organic substance which exists in two
states of oxidations.
a. Redox indicators b. oxidizing agents c. catalysts_____ 11.
Ferrous ions in dichromate process are considered as-
a. oxidizing agent b. reducing agent c. redox indicators
______ 12. What phenomenon do you prevent when you use ferrous
solutions in the presence of acid?
a. Precipitation of basic salts b. hydrolysis c. decomposition
of Fe+2 ions______ 13. The gram-equivalent of potassium dichromate
is-
a. 1/6 of the gram molecular weight of potassium dichromateb.
1/3 of the gram molecular weight of potassium dichromatec. 1/2 of
the gram molecular weight of potassium dichromate
______ 14. Which of the following phrases is not correct?
a. Oxidation of Fe+2
ions by chlorine c. oxidation of Fe+2
ions by dichromate ionsb. reduction of Fe+2 ions by chlorine
______ 15. In the reaction: 5 Sn+2
+ 2 MnO4-+ 16 H
+-------> 5 Sn
+4+ 2 Mn
+2+ 8 H2O
Which of the following is false?
a. The reaction is in the presence of an acidb. Sn+2 ions serves
as reducing agents in the reactionc. Mn in MnO4- oxidizes to form
Mn+2 ions
