When an iron object is plated with tin, tin does not act as sacrificial anode in protecting against corrosion, because

• tin is more reactive than iron

• tin is less reactive than iron

• reactivity of tin and iron is same

• tin is oxidising agent while iron is not so

Choose the correct statement from the following.

• The greater positive value of ${\mathrm{E}}_{\mathrm{OP}}^{°}$ indicates greater reactivity of metal

• F^- is strong oxidant while Cu²⁺ is weak reductant

• The metals placed above Mg in the electrochemical series do not decompose water at ordinary temperature

• Oxides of Hg do not decompose on heating

The effective neutron capture radius of a nucleus having a cross- section of 1.0 barr is [ Given, 1 barr = 1.0 x 10^-24 cm²]

• 5.6 x 10^-13cm

• 4.3 x 10^-13cm

• 2.3 x 10^-11 cm

• 5.6 x 10^-24cm

624.

C₆H₅ - NHOH + C₆H₅ - NO $\stackrel{\mathrm{NaOH}}{\to }$(X), (X) formed in the above reaction is

• 

• (C₆H₅)₂NOH

• 

• 

Standard electrode potential of three metals X, Y and Z are -1.2 V, +0.5 V and -3.0 V respectively. The reducing power of these metals will be

• Y > X > Z

• Z > X > Y

• X > Y > Z

• Y > Z > X

If the ${\mathrm{E}}_{\mathrm{cell}}^{°}$ for a given reaction has a negative value then which of the following gives the correct relationships for the values of $∆$G° and K_eq?

• $∆\mathrm{G}°$ < 0; K_eq > 1

• $∆\mathrm{G}°$ <0; K_eq < 1

• $∆\mathrm{G}°$ > 0; K_eq < 1

• $∆\mathrm{G}°$ > 0; K_eq > 1

The conductivity of 0.001028 mol L^-1 acetic acid is 4.95 x 10^-5 S cm^-1. Find out its dissociation constant if Λ_m for acetic acid is 390.5 S cm^-1 mol^-1.

• 2.18 x 10^-5 mol^-1L^-1

• 1.78 x 10^-5 mol L^-1

• 3.72 x 10^-4 mol L^-1

• 2.37 x 10^-4 mol L^-1

Which of the following statement is not correct about an inert electrode in a cell?

• It does not participate in the cell reaction.

• It provides surface either for oxidation or for reduction reaction.

• It provides surface for conduction of electrons.

• It provides surface for redox reaction

Which of the following statement is correct?

• E_cell and ${∆}_{\mathrm{f}}$G of cell reaction both are extensive properties.

• E_cell and ${∆}_{\mathrm{f}}\mathrm{G}$ of cell reaction both are intensive properties

• E_cell in the intensive property while ${∆}_{\mathrm{r}}\mathrm{G}$ of cell reaction is an extensive property

• E_cell is an extensive property while ${∆}_{\mathrm{r}}\mathrm{G}$ of cell reaction is an intensive property.

When Br₂ is treated with aqueous solutions of NaF, NaCl, NaI separately

• F₂, Cl₂ and I₂ are liberated

• only F₂ and Cl₂ are liberated

• only I₂ is liberated

• only Cl₂ is liberated