CBSE
Multiple Choice QuestionsAssertion: Conductivity of all electrolytes decreases on dilution.
Reason: On dilution number of ions per unit volume decreases.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
For Zn2+| Zn, = -0.76 then EMF of the cell Zn/Zn2+(+1M)|2H+ (1M)| H2(1 atm) will be
-0.76 V
0.76 V
0.38 V
-0.38 V
Electrode potential of hydrogen electrode is 18 mV, then [H+] is
0.2
1
2
5
Assertion : Sodiumacetate on Kolbe's electrolysis gives methane.
Reason : Methyl free radical is formed at cathode.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion : Magnesium is extracted by the electrolysis of fused mixture of MgCl2, NaCl and CaCl2.
Reason : Calcium chloride acts as a reducing agent.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
If a salt bridge is removed between the half cells , the voltage :
decreases to zero
increases
increases rapidly
do not change
During electrochemical process :
Gibbs free energy increases
Gibbs free energy remains constant
no prediction can' be made about Gibbs free energy
Gibbs free energy decreases
A factory produces 40 kg of calcium in two hours by electrolysis. How much aluminium can be produced by same current in 2 hours if current efficiency is 50%?
22 kg
18 kg
9 kg
27 kg
The standard emf of a cell , involving one electron change is found to be 0.591 V at 25o C . The equilibrium constant of the reaction is :
(F = 96500 C mol-1 , R = 8.314 JK-1mol-1)
1.0 x 101
1.0 x 105
1.0 x 1010
1.0 x 1030
A complex PtCl4.5NH3, shows a molar conductance of 402 ohm-1 cm2mol-1 in water and precipitates three moles ofAgCl with AgNO3 solution. The formula of the complex is
[Pt(NH3)6]Cl4
[Pt(NH3)4Cl2]Cl2
[Pt(NH3)5Cl]Cl3
[Pt(NH3)3Cl3]Cl
