how do metals react with acids? explain through examples.
Metals react with acids to form the corresponding metal salt and hydrogen gas. The general equation for this process can be represented as
Metal + Acid → Metal salt + Hydrogen gas
However, all metals will not react with acids. Only those metals which are more reactive than hydrogen and so placed above hydrogen in the activity series will show the above reaction. For example, zinc is more reactive than hydrogen. So, it will react will dilute HCl to form zinc chloride and hydrogen gas. Silver, being less reactive than hydrogen does not react with dilute HCl.
Zn (s) + 2HCl (aq) → ZnCl2 (aq) + H2 (↑)
Ag (s) + HCl → no reaction
Another important point to note is that hydrogen gas is not evolved when a metal reacts with nitric acid. This is because nitric acid is a strong oxidising agent. It oxidises the hydrogen gas produced in the reaction to form water and itself gets reduced to nitrogen oxides like nitric oxide, nitrogen dioxide and nitrous oxide.