Question

How do metals react with dilute acids. Explain with the help of an example.

Answer 1

When a metal reacts with dilute acid, salts are formed. During this reaction hydrogen gas is evolved. In other words, when a metal is added to dilute acids, salt and hydrogen gas are formed. 
Process
Sulfate salts and chloride salts are formed when metals react with dilute sulfuric acid and hydrochloric acid. Some metals reacts vigorously with dilute sulfuric acid or hydrochloric acid for example, potassium, sodium, lithium and calcium.

Answer 2

Given that,

A metal and a dilute acid.

To find,

Reaction of metals with dilute acids.

Solution,

When metals reacts with dilute acids salts are formed along with evolution of hydrogen gas.

For example :

Magnesium is a metal. It is denoted Mg. Hydrochloric acid is one of the dilute acid. The reaction is as follows :

$Mg+HCl\rightarrow MgCl_2+H_2$

Here, $MgCl_2$ is magnesium chloride and it is a metal salt and $H_2$ is hydrogen gas.