In electrolysis, if the duration of the passage of current is doubled, the mass liberated is :
Doubled
Halved
Increased four times
Remains the same
Two electrolytic cells containing and respectively are connected in series and a current is passed through them until 1 mg of copper is deposited in the first cell. The amount of silver deposited in the second cell during this time is approximately
[Atomic weights of copper and silver are respectively 63.57 and 107.88] :
1.7 mg
3.4 mg
5.1 mg
6.8 mg
Electroplating does not help in :
Fine finish to the surface
Shining appearance
Metals to become hard
Protect metal against corrosion
The negative Zn pole of a Daniel cell, sending a constant current through a circuit, decreases in mass by 0.13g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is :
0.242 g
0.190 g
0.141 g
0.126 g
The value of current required to deposit 0.972 gm of chromium in 3 hours if the E.C.E. of chromium is 0.00018 gm per coulomb, is :
1 amp
1.5 amp
0.5 amp
2 amp
The electrochemical equivalent of a material in an electrolyte depends on :
The nature of the material
The current through the electrolyte
The amount of charge passed through electrolyte
The amount of material present in electrolyte
On passing 96500 coulomb of charge through a solution the amount of copper liberated is :
64 gm
32 gm
32 kg
64 kg
Who among the following scientists made the statement –"Chemical change can produce electricity"?
Galvani
Faraday
Coulomb
Thomson
The chemical equivalent of silver is 108. If the current in a silver voltmeter is 2 Amp., the time required to deposit 27 grams of silver is :
8.57 hrs
6.70 hrs
3.35 hrs
12.50 hrs
Two voltmeters, one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltmeters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are and respectively the charge which flows through the silver voltmeter
is :