Which of the following facts are true ?

Options

A. If `E^(0)(M^(n+)//M)` is negative , `H^(+)` will be reduced to `H_2` by the metal M.
B. If `E^(0) (M^(n+)//M)` is positive , `M^(n+)` will be reduced to M by `H_2`
C. In a cell , `M^(n+)//M` assembly is attached to hydrogen -half cell. To produce spontaneou cell reaction, metal M will act as negative electrode if the potential `M^(n+)//M` is negative. It will serve as positive electrode , if `M^(n+)//M` has a positive cell potential.
D. Compound of active metal (Zn,Na, Mg) are reducible by `H_2` where as those of noble metals (Cu , Ag , Au) are not reducible

Answer

A, B, C

Explanation

a) `2H^(+) + 2e^(-) overset("red")to H_2 , "b)" M^(n+) + n e^(-) overset("red")to M`
c) `M^(n+)//M` assembly attached to hydrogen half cell
To produce spotaneous cell reaction
M ` to -ve` electrode , `M^(n+)//M` is negative
It acts as +ve electrode , if `M^(n+)//M` has positive cell potential