[Fish200398]

Pt2+  +  2e   ->  Pt  E = 1.188 V
PtCl4 2-   +   2e   -> Pt  + 4Cl -  E = 0.755 V
NO3 -   +   4H+    +  3e     ->   NO    + 2H2O   E = 0.960 V
from above, we conclude that platinum wil dissolve in aqua regia
because
nitric acid can oxidize platinum based on potential reduction standard above


which statement is true and wheter they connect each other

1st statement is true
2nd statement must be true then..
but why nictric acid can oxidize platinum when E platinum is higher than NO3 aka platinum easily reduced than NO3 ?

in this PtCl4 2-   +   2e   -> Pt  + 4Cl -  E = 0.755 V
platinum is being reduced then why platinum dissolve in HCl + HNO3 (aqua regia) ?

[mjc123]

These reactions are equilibria. What is being considered is the possibility of the reverse reaction, i.e. the oxidation of platinum.
Can nitric acid oxidise Pt to Pt²⁺?
Can nitric acid, in the presence of Cl^-, oxidise Pt to PtCl₄^2-?

[Fish200398]

no it cant, because E red platinum greater than NO3 and Cl

[mjc123]

Which question are you answering, and what does your answer mean?

[Fish200398]

Can nitric acid oxidise Pt to Pt2+?
i think no, because potential reduction of Pt is higher than NO3
Can nitric acid, in the presence of Cl-, oxidise Pt to PtCl42-?
i think no, because potential reduction of Pt is higher than NO3

[mjc123]

Can nitric acid, in the presence of Cl-, oxidise Pt to PtCl42-?
i think no, because potential reduction of Pt is higher than NO3

What is being reduced (in the reduction potential equations)? Not Pt!
Why do you think you are given the second equation?