Q.1
For electrochemical cell M|M+ || X- |X, Eo(M+/M)=0.44 Vand Eo(X/X-)=0.33 VFrom this data, one can deduce that [ IIT 2000]
  • a) M + X → M+ + X- is the spontaneous reaction
  • b) M+ + X- → M + X is the spontaneous reaction
  • c)Ecell=0.77 V
  • d)Ecell=-0.77 V
Q.2
The molar conductivity is maximum for the solution of concentration
  • a) 0.004 M
  • b) 0.002 M
  • c) 0.005 M
  • d) 0.001 M
Q.3
The emf of the cell Ag|Ag+( 0.1M)|| Ag+( 1M) | Ag at 298K is
  • a)0.59 V
  • b) 5.9 V
  • c)0.059 V
  • d)0.0059 V
Q.4
resistance of a conductivity cell filled with solution of an electrolyte of concentration 0.1M is 100 Ω. the conductivity of this solution is 1.29 Sm-Resistance of the same cell when filled with 0.2M of the same solution is 520Ω. The molar conductivity of 0.02M solution of the electrolyte will be [ AIEEE 2006]
  • a) 124 × 10-4S m2 mol-1
  • b) 1240 × 10-4S m2 mol-1
  • c)1.24 × 10-4S m2 mol-1
  • d)12.4 × 10-4S m2 mol-1
Q.5
The Eo (M3+ / M2+) values for Cr, Mn, Fe and Co are -0.41, +1.57, +0.77 and +1.97 respectively . For which one of these metals the change in oxidation state from +2 to +3 is easiest? [ AIEEE 2004]
  • a) Cr
  • b) Co
  • c)Fe
  • d)Mn
Q.6
For the redox reaction Zn + Cu2+(0.1M) → Zn2+(1M) + Cu taking place in cell, Eocell is 1.1 V. Ecell for the cell will be [ AIEEE 2003]
  • a) 2.14 V
  • b) 1.8 V
  • c) 1.07 V
  • d) 0.82 V
Q.7
The half cell reaction for the corrosion are 2H+ + ½ O2 → H2O ; Eo=-1.23 V Fe2+ + 2e- → Fe ; Eo=- 0.44 V Find ΔGo ( in kJ) for the over all reaction [ IIT 2005]
  • a)-76
  • b) -322
  • c)-161
  • d)-152
Q.8
Standard reduction electrode potential of three metals A, B and C are respectively +0.05V, -3.0V and -1.2V. The reducing powers of ..[ AIEEE 2003]
  • a) B > C > A
  • b) A > B > C
  • c)C > B > A
  • d)A > C > B
Q.9
Calculate the volume of H2 gas at NTP obtained by passing 4 amperes through acidified H2O for 30 minutes
  • a) 0.0836 L
  • b) 0.0432 L
  • c)0.1672 L
  • d)0.836 L
Q.10
Consider the following Eo values Eo ( Fe3+/ Fe2+ )=+0.77 V , Eo ( Sn2+/ Sn )=-0.14V Under standard conditions, the potential for the reaction Sn + 2Fe3+ → 2Fe2+ + Sn2+ is .. [ AIEEE 2004]
  • a) 1.68 V
  • b) 0.63 V
  • c) 0.91 V
  • d) 1.4 V
Q.11
The standard reduction potential at 298K for the following half reactions are given against each, which willa act as best reducing agent Zn2+ + 2e- → Zn ; -0.762 V Cr3+ + 3e- → Zn ; -0.740 V 2H+ + 2e- → H2 ; -0.00 VFe3+ + e- → Fe2+ ; -0.762 V
  • a)Zn
  • b) Cr
  • c)H2
  • d)Fe2+
Q.12
Standard electrode potential (Eo) for OCl-/Cl- and Cl- / (1/2) Cl2 are respectively 0.94 V and -1.36 V. The Eo value for OCl-/ Cl2 will be
  • a) -0.42 V
  • b) -2.20 V
  • c)0.52 V
  • d)1.04 V
Q.13
The oxidation state of chromium in Cr(CO)6 is ..[AIIMS 1993]
  • a)0
  • b) +2
  • c)-2
  • d)+6
Q.14
Given The value of standard electrode potential for the changeFe3+ + e- → Fe2+ will be.. [ AIEEE 2009]
ch-7_que_no-72_img_no1.png
  • a) -0.072 V
  • b) 0.85 V
  • c) 0.770 V
  • d) -0.270 V
Q.15
The unit of molar conductivity is
  • a)Ω cm2 mol-1
  • b) Ω-1 cm2 mol-1
  • c)Ωcm2 mol-1
  • d)Ω-1 cm-2 mol-1
Q.16
In corrosion of iron
  • a) An electrochemical ( galvanic cell) is formed in which Fe acts as anode and cathode where O2 is reduced
  • b) Electrons flow from anode to cathode through the metal while ions flow through the water droplets
  • c)Dissolved O2 oxidises Fe2+ to Fe3+ before it is deposited as rust ( Fe2 . H2O)
  • d)All of the above takes place
Q.17
A standard hydrogen electrode has zero electrode potential because [ IIT 1997]
  • a) Hydrogen is easier to oxidise
  • b) This electrode potential is assumed to be zero
  • c)Hydrogen atom has only electron
  • d)hydrogen is the lightest element
Q.18
The oxidation potential for the half cell reactions are Zn → Zn+ +2e- ; Eo=+0.76 V Fe → Fe+ +2e- ; Eo=+0.41 V The emf of cell reaction Fe+ + Zn → Zn+ + Fe is [IIT 1981]
  • a) -0.35 V
  • b) +0.35 V
  • c) +1.17 V
  • d) 0.117 V
Q.19
Given The potential of cell Cr|Cr3+(0.1M) || Fr2+(0.01M)| Fe is [ AIEEE 2008]
ch-7_que_no-77_img_no1.png
  • a)-0.26 V
  • b) 0.26 V
  • c)0.339 V
  • d)-0.339 V
Q.20
A gas X at 1 atm pressure is bubbled through a solution containing a mixture of 1M Y- ions and 1M Z- ions at 125°C. If reduction potential of Z > Y; X > Z then
  • a) Y will oxidise Z and not X
  • b) Y will oxidise X and not Z
  • c)Y will oxidise X and Z
  • d)Y will reduce both X and Z
Q.21
Best way to prevent rusting of iron is by
  • a) Making iron cathode
  • b) Putting it in saline water
  • c)Both of these
  • d)None of these
Q.22
Saturated solution of KNO3 is used to make salt bridge because [ IIT 2001]
  • a) Velocity of K+ is greater than that of NO3-
  • b) Velocity of NO3- is greater than that of K+
  • c) Velocity of both K+ and NO3-
  • d) KNO3 is highly soluble in water
Q.23
Which of the following is not a redox reaction? [ AIIMS 1993]
  • a)CaCO3 → CaO +CO2
  • b) O2 + 2H2 → 2H2O
  • c)Na + H2O → NaOH + ½ H2
  • d)MnCl3 → MnCl2 + ½Cl2
Q.24
Which substance serves as reducing agent in the following reaction?14H+ Cr2O7- + 3Ni → 2Cr3+ + 7H2O + 3Ni2+ [ CBSE PMT 1994]
  • a) H2O
  • b) Ni
  • c)H+
  • d)Cr2O72-
Q.25
Nitric oxide acts as a reducing agent in the reaction [ DEC 1994]
  • a) 4NH3 + 5O2 → 4NO + 6H2O
  • b) 2NO + 3I2 +4 H2O → 2NO3- + 6I- + 8H+
  • c)2NO + H2SO3 → N2O + H2SO4
  • d)2NO + H2S → N2O + S + H2O
Q.26
In which of the following reaction, hydrogen is acting as an oxidising agent? [ MPPMT 1987]
  • a) With iodine to give hydrogen iodide
  • b) With lithium to give lithium hydride
  • c) With nitrogen to give ammonia
  • d) With sulphur to give hydrogen sulphide
Q.27
When SO2 is passed through solution of potassium iodate, the oxidation state of iodine changes from .. [ Roorkee 1990]
  • a)+5 to 0
  • b) +5 to -1
  • c)-5 to 0
  • d)-7 to -1
Q.28
M is the molecular weight of KMnOthe equivalent weight of KMnO4 when it is converted into K2MnO4 is .. [ AFMC 1994]
  • a) M
  • b) M/3
  • c)M/5
  • d)M/7
Q.29
In the reaction, 3Br2 + 6CO32- + 3H2O → 5Br- + BrO3- + 6HCO3- [ MP PMT 1995, Pb CET 1996]
  • a) Bromine is oxidised and carbonate is reduced
  • b) Bromine is reduced and water is oxidised
  • c)Bromine is neither reduced nor oxidised
  • d)Bromine is both reduced and oxidised
Q.30
Which of the following elements has least oxidation number [ Rajasthan PMT 1998]
  • a) Ni(CN)4
  • b) Ni(CO)4
  • c) Fe2O3
  • d) SF4
0 h : 0 m : 1 s