The optimum reaction conditions for the preparation of 2,4-dinitrophenol from phenol and nitric acid are as follows:1. Concentration of reactants:- Phenol: Typically, a 1:1 molar ratio of phenol to nitric acid is used. For example, if you are using 1 mole of phenol, you would use 1 mole of nitric acid.- Nitric acid: Concentrated nitric acid 65-70% is commonly used for this reaction.2. Temperature: The reaction should be carried out at a temperature between 0C and 5C. This is usually achieved by cooling the reaction mixture in an ice bath.3. Reaction time: The reaction time can vary depending on the scale of the reaction and the efficiency of stirring. Generally, the reaction is complete within 1-2 hours.It is important to note that the preparation of 2,4-dinitrophenol can be hazardous due to the potential for explosion and the toxic nature of the compound. Proper safety precautions should be taken, including working in a well-ventilated area, wearing appropriate personal protective equipment, and following standard laboratory safety procedures.