inorganic chemistry

Question

A certain metal displays no acid-base chemistry below neutral pH but is oxidized from M to M²⁺ at –3.3V and from M²⁺ to M³⁺ at –0.5V. Above neutral pH, the 3+ ion exists only as the insoluble hydroxide. At pH=14, this insoluble hydroxide resists reduction to M²⁺ down to –2.0V. Draw a reasonable Pourbaix diagram for this metal. Explain your answer.

Answer 1

Metal Oxidized from M to M^2+ at -3.3V

From M^2+ to M^3- at -0.5v

Above neutral PH, exists only as M(OH)_3

M(OH)_3 resists reduction to M^2+ down to -2.0 V

The pourbaix diagram for this metal is as follows:

[No opportunities for drawing here, you can email me if you need the drawing diagram]

So, below -3.3 V metal exists as metal (M).

From potential -3.3 V to -0.5 V metal exists as M²⁺.

Potential above -0.5 V and pH less than 7, M³⁺ is stable.