Nitric acid is a strong oxidising in the concentrated state than dilute state

In dilute state nitric acid ionises as NO₃ ^- and H⁺ in water, thus behaving as an acid, whereas in concentrated state it behaves as an oxidising agent as it is not ionised as mentioned above.
So, due to this reason nitric acid is a strong oxidising agent in concentrated state than in dilute state.

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