91影视

A voltaic cell with Ni/${\text{Ni}}^{\text{2}}$and Co/C half-cells has the following initial concentrations$\left[{\text{Ni}}^{\text{2 +}}\right]\mathbf{\text{= 0.80M;}}\left[{\text{Co}}^{\text{2 +}}\right]\mathbf{\text{=0.20M}}$.

(a) What is the initial${\mathbf{\text{E}}}_{\mathbf{\text{cell}}}$?

(b) What is$\left[{\text{Ni}}^{\text{+ 2}}\right]$ when${\mathit{E}}_{\mathbf{c}\mathbf{e}\mathbf{l}\mathbf{l}}$reaches 0.03V?

(c) What are the equilibrium concentrations of the ions?

Are spectator ions used to balance the half-reactions of a redox reaction? At what stage might spectator ions enter the balancing process?

Which of the following metals are suitable for use as sacri铿乧ial anodes to protect against corrosion of underground iron pipes? If any are not suitable, explain why:

(a) Aluminium

(b) Magnesium

(c) Sodium

(d) Lead

(e) Nickel

(f) Zinc

(g) Chromium