Prof. Anil Thomas and Prof. Santosh Yadav Solutions for Chapter: Electrochemistry, Exercise 3: Competitive Thinking

Reducing powers of A, B, C and D are w, x, y and z respectively such that z > y > x > w. The one which will displace all others is______.

The value of ${\mathrm{E}}_{\mathrm{red}}^{\circ }$for metals $\mathrm{A},\mathrm{B} \text{and} \mathrm{C}\text{ is} 0.34 \mathrm{V}, -0.80 \mathrm{V} \text{and} -0.46 \mathrm{V}$, respectively. State the CORRECT order for their ability to act as reducing agent.

The standard reduction potential for ${\mathrm{Zn}}^{\mathrm{2+}}/\mathrm{Zn}, {\mathrm{Ni}}^{\mathrm{2+}}/\mathrm{Ni} \text{and} {\mathrm{Fe}}^{\mathrm{2+}}/\mathrm{Fe}$ are $-0.76 \mathrm{V}, -0.23 \mathrm{V} \mathrm{and} -0.44 \mathrm{V}$, respectively. The reaction $\mathrm{X}+{\mathrm{Y}}^{+2}\stackrel{}{\to } {\mathrm{X}}^{2+}+\mathrm{Y}$ will be spontaneous when ______.

The ${\mathrm{E}}_{{\mathrm{M}}^{3+}/{\mathrm{M}}^{2+}}^{\circ }$ values for $\mathrm{Cr}, \mathrm{Mn}, \mathrm{Fe} \text{and} \mathrm{Co}\text{ are} -0.41 \mathrm{V}, +1.57\mathrm{V}, +0.77 \mathrm{V} \text{and} +1.97 \mathrm{V}$, respectively. For which one of these metals, the change in the oxidation state from $+2 \text{to} +3$ is the easiest?

The standard oxidation potential values of $\mathrm{A},\mathrm{B},\mathrm{C} \text{and} \mathrm{D} \text{are} -0.03\mathrm{V}, 0.108 \mathrm{V}, -0.07\mathrm{V} \text{and} 0.1\mathrm{V}$, respectively. The non-spontaneous cell reaction takes place between________.       
 

During galvanization of iron, which metal is used for coating iron surface?

Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because_____.

The process in which the metal surface is made inactive is called ______.