Which graph correctly correlates Ecell as a function of concentrations for the cell (for different values of M and M') ?

Zn(s)+Cu2+(M)Zn2+(M')+Cu(s);
Ecell=1.10V
X-axis:log10Zn2+Cu2+,Y-axis:Ecell

1.                         2.    
3.                         4. 

Subtopic:  Nernst Equation |
 65%
Level 2: 60%+
Hints

An iron ship is continuously exposed to seawater, which can cause corrosion (rusting) of its hull.
Which of the following methods provides the most effective long-term protection
to the iron at the bottom of the ship? 

1. Coat the iron surface with red lead oxide paint

2. Cover the iron surface with a layer of tin (tin plating) 

3. Attach blocks of magnesium to the iron hull

4. Attach blocks of lead to the iron hull

Subtopic:  Corrosion |
Level 3: 35%-60%
Hints

The electrode potentials for

Cu2+(aq)+e-Cu+(aq)
andCu+(aq)+e-Cu(s)

are +0.15 V and +0.50 V respectively. The value of ECu2+Cuwill be

1. 0.325 V

2. 0.650 V

3. 0.150 V

4. 0.500 V

Subtopic:  Relation between Emf, G, Kc & pH |
 55%
Level 3: 35%-60%
Hints

advertisementadvertisement

The Zn acts as sacrificial or cathodic protection to prevent rusting of iron because:

1. EOP of Zn < EOP of Fe

2. EOP of Zn > EOP of Fe

3. EOP of Zn = EOP of fe

4. Zn is cheaper than iron

Subtopic:  Corrosion |
 74%
Level 2: 60%+
Hints

The standard reduction potential for Fe2+|Fe and Sn2+|Sn electrodes are -0.44 V and -0.14 V respectively. For the cell reaction,

Fe2+ + Sn   Fe + Sn2+, the standard Emf is - 

1. +0.30 V

2. 0.58 V

3. +0.58 V

4. -0.30 V

Subtopic:  Electrode & Electrode Potential |
 64%
Level 2: 60%+
Hints
Links

On electrolysing a solution of dilute H2SO4 between platinum electrodes, the gas evolved at the anode and cathode are respectively:

1. SO2 and O2

2. SO3 and H2

3. O2 and H2

4. H2 and O2

Subtopic:  Electrode & Electrode Potential |
 64%
Level 2: 60%+
Hints

advertisementadvertisement

In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam because :

1. Hg is more inert than Pt

2. More voltage is required to reduce H+ at Hg than at Pt

3. Na is dissolved in Hg while it does not dissolve in Pt

4. Concentration of H+ ions is larger when Pt electrode is taken.

Subtopic:  Electrode & Electrode Potential |
Level 3: 35%-60%
Hints

If mercury is used as cathode in the electrolysis of aqueous NaCl solution, the ions discharged at cathode are:

1. H+

2. Na+

3. OH-

4. Cl-

Subtopic:  Electrode & Electrode Potential |
 59%
Level 3: 35%-60%
Hints

The standard reduction electrode potentials of three metals X, Y, and Z are given as -1.2 V, +0.5 V, and -3.0 V, respectively. Based on these values, what is the correct order of their reducing power?

1. Y > X >Z 2. Z > X > Y
3. X > Y > Z 4. Y > Z > X
Subtopic:  Electrochemical Series |
 83%
Level 1: 80%+
Hints
Links

advertisementadvertisement

A gas X at 1 atm is bubbled through a solution containing a mixture of 1MY- and 1MZ- at 25°C. If the reduction potential of Z > Y > X, then:

1. Y will oxidise X and not Z

2. Y will oxidise Z and not X

3. Y will oxidise both X and Z

4. Y will reduce both X and Z

Subtopic:  Electrochemical Series |
 67%
Level 2: 60%+
Hints