Tag: electrochemistry

Questions Related to electrochemistry

Which statement is not correct ?

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. Conductance of an electrolytic solution increase with dilution

  2. Conductance of an electrolytic solution decrease with dilution

  3. specific conductance of an electrolytic solution decrease with dilution

  4. Equivalent conductance of an electrolytic solution increase with dilution

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Correct Option: C

Pure water consists almost entirely of:

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. molecules

  2. ions

  3. atoms

  4. ions and molecules

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Correct Option: A
Explanation:

Water has very low ionisation constant so it dissociates very low and pure water is consists almost entirely of molecules.

Molten potassium chloride conducts electricity due to the presence of  _______ .

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. free electron

  2. free ions

  3. free molecules

  4. atom of potassium & chloride

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Correct Option: B

Which of the following solid is an electronic conductor?

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. $NaCl$

  2. Diamond

  3. $CuS$

  4. $KCl$

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Correct Option: C
Explanation:

Only CuS solid conducts electricity. NaCl and KCl are electrolytic conductor and diamond is non-conductor.

Hence, correct option is C.

We can expect that pure water:

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. will not normally conduct electricity

  2. will normally conduct electricity

  3. slightly conduct electricity

  4. completely conduct electricity

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Correct Option: A
Explanation:

Water has very low ionisation constant so it dissociates very low and pure water  consists almost entirely of molecules; as no of ions are very less in pure water so normally it will not conduct electricity.

Which modifications are necessary to determine the resistance of solution by the usual method of measurements on Wheatstone's bridge principle?

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. A.C. should be used

  2. A conductivity cell is used

  3. Galvanometer is replaced by magic eye or headphone arrangement

  4. All of the above

Show answer
Correct Option: D
Explanation:

All of the following modifications are necessary to determine the resistance of solution by the usual method of measurements on Wheatstone's bridge principle.


(A) A.C. should be used.
(B) A conductivity cell is used.
(C) The galvanometer is replaced by magic eye or headphone arrangement.

If D.C. is used, electrolyte solution will go electrolysis and the change in concentration during the passage of current will not allow reaching the steady value of the null point. In A.C. galvanometer does not work. Also to put the solution at one end in the gap of the meter bridge, a conductivity cell is needed.

Hence, the correct option is $D$

Assertion: Nickel is a metal and it conducts electricity through its valence shell electrons.
Reason: Nickel sulphate solution conducts electricity through its ions.
metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. Both Assertion and Reason are true and Reason is the correct explanation of Assertion

  2. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion

  3. Assertion is true but Reason is false

  4. Assertion is false but Reason is true

  5. Both Assertion and Reason are false

Show answer
Correct Option: B
Explanation:

Nickel is a metal and it conducts electricity through its valence shell electrons while nickel sulphate solution conducts electricity through its ions (formed by dissociation of nickel sulphate solutions).

Which one of the following solution will conduct electricity?

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. Sugar in water

  2. Sugar in ethyl alcohol

  3. Iodine in ethyl alcohol

  4. Magnesium chloride water

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Correct Option: D
Explanation:

Solution which contains free ions conducts electricity.

Since, Magnesium Chloride aqueous solution will have Mg ions. Hence, it will conduct electricity

A solution of sodium in liquid ammonia at $-33^oC$ conducts electricity. On cooling, the conductivity of this solution _______.

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. decreases

  2. increases

  3. remains same

  4. becomes 0

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Correct Option: A
Explanation:

A solution of sodium in liquid ammonia at $-33^oC$ conducts electricity. On cooling, the conductivity of this solution ...... The conductivity of the solution is due to presence of ammoniated electrons. With decrease in the temperature, the mobility of ammoniated electrons decreases due to which the electrical conductivity decreases.

An aluminium wire is:

metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

  1. non-electrolyte

  2. weak electrolyte

  3. metallic conductor

  4. none of these

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Correct Option: C
Explanation:

Aluminium is metal so its wire will act as metallic conductor and it conducts electricity due to valence shell electrons.