Copper dissolves in dilute HNO_3 but not in dilute HCl. Explain.

1.	Copper dissolves in dilute HNO_3 but not in dilute HCl. Explain.
Answer» Solution :Since `E^@` of `Cu^(2+)\|Cu` electrode ,(+0.34V) is higher than that of `H^+\|1/2H_2` (0.0V) , therefore , `H^+` IONS cannot oxidise Cu to `Cu^(2+)` ions and consequently, COPPER does not dissolve in dil . HCl on the other hand , the electrode potential of `NO_3^(-)` ion, `NO_3^(-) \|NO(+0.97V)` is higher than that of copper electrode and hence , it can oxidise `Cu" to "Cu^(2+)` and hence copper DISSOLVES in dil . `NHO_3^(-)`.

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