E-PolyLearning

1. If acidified Potassium Dichromate(VI) (K₂Cr₂O₇) acts as oxidizing agent, color changes from
a. orange to red
b. orange to green
c. yellow to green
d. yellow to red
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Answer: (c).yellow to green

2. In an acidified solution of Potassium Dichromate(VI) (K₂Cr₂O₇), Dichromate ion (Cr₂O₇-2) becomes reduced to
a. Chromate (V) ions
b. Chromium (III) ions
c. Chromium (II) ions
d. Chromium (VI) ions
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Answer: (b).Chromium (III) ions

3. Oxidation involves
a. loss of hydrogen
b. loss of oxygen
c. gain in hydrogen
d. gain in electrons
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Answer: (a).loss of hydrogen

4. In a reaction between CuSO₄(s) and Zn(s),
a. Zinc experiences an increase in the oxidation state
b. undergoes oxidation
c. Zinc undergoes oxidation
d. all of these
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Answer: (d).all of these

5. Old paintings became discolourised due to
a. Lead Sulphide PbS
b. Lead Sulphate PbSO₄
c. Lead Chloride PbCl₂
d. Lead Oxide PbO
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Answer: (a).Lead Sulphide PbS

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