what are concentrated and dilute acids?
some examples of concentrated and dilute acids-
how to dilute an acid?
Please refer to the following link
Some examples are concentrated sulphuric acid, dilute sulphuric acid, concentrated HCl, dilute HCl, etc.
We can dilute an acid by pouring acid to the water slowly and carefully, if water is added to some strong acid like sulphuric acid then it may explode and all the acid from the vessel may spill on the person and near by object.