Silver Mirror Test
This kind of reaction is called tollens reaction. where complex ion and metal will form.
Equipment and Chemical: Rounded Bottom glass container (flask),AgNO3 , 1M NH4OH(aqeous) , Thermometer, graduated cylinder, 1L Beaker, test tubes, water, hotplate, Distilled water. Glucose ( C6H12O6 )
Procedure: Apply all procedure for safety and obtain goggles. Make about 0.1M Silver Nitrate aqueous solution. make about 75 mL of Silver Nitrate solution. Now add about 5-7mL of Ammonium Hydroxide into solution. Observe the color of Solution. DO NOT STIR. Now add another 5-7 mL of Ammonium Hydroxide .This time color will disappear. Add about 5-7 of grams of glucose into 10-15 mL of distilled water. Add glucose solution into Silver nitrate Solution. Take this solution and place in 1L beaker (add water in beaker). Heat up the water about 70-75 C. DO NOT BOIL WATER. after than wait about 3-4 minutes. Finally read Continued Procedure to discard solution.
Observation & Discussion:
Movie: Silver Mirror Test
When ammonium hydroxide added to silver nitrate , silver oxide (Ag2O) precipitate will form. By adding ammonium hydroxide solution again , precipitate will disappear. There are three observation made. In first observation solution is placed before into water bath which is clear. Now solution is heated gradually. As solution is heated it turns into henna colored (Brownish green) solution. That is Ag(NH3)+ complex ion solution. Glucose will reduce the Ag+ to Ag and NH3 will be separated. In third observation flask turn into silver color. It indicates formation of silver. Whole flask is not silver but silver is stick on the wall of flask. Access of solution will left in flask.
This is a redox reaction. Ag+ reduced to Ag by glucose. NH3 and H2O are other partially product.
Continued Procedure: When Experiment is completed, discard the solution from the flask otherwise it peer off the silver layer. Now check your image in flask. Since flask is rounded, it work as Convex mirror.