Silver Nitrate Test for Alkyl Halides

Avoid spilling alcoholic silver nitrate on your skin because staining may result. If you do come into contact with the solution, immediately flood the affected area with water. 

Preparation Sign in at www.cengage.com/login to read the MSDSs for the chemi- 

Add 1 drop of the alkyl halide to 2 mL of a 0.1 A//solution of silver nitrate in 95% ethanol. If no reaction Is observed within 5 min at room temperature, warm the mixture in a beaker of boiling water and observe any change. Note the color of any precipitates silver chloride is white but turns purple on exposure to light, silver bromide is pale yellow, and silver iodide is dark yellow. If there is any precipitate, add several drops of 1 M nitric acid solution to it. and note any changes the silver halides are insoluble in acid. To determine expected reactivities, test known primary, secondary, and tertiary halides in this manner. If possible, use alkyl iodides, bromides, and chlorides so that differences in halogen reactivity can also be observed. 

Neutralize and then filter all test mixtures and place the filter cake in a container for recovered silver halides. Flush the filtrate down the drain. 

Another method for distinguishing between primary, secondary, and tertiary halides makes use of sodium iodide dissolved in acetone. This test complements the alcoholic silver nitrate test, and when these two tests are used together, it is possible to determine the gross structure of the attached alkyl group with reasonable accuracy. 

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