Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
-----------------
sulphuric acid : H2SO4
ethanol : CH3CH2OH
sodium nitrite : NaNO2
Class:
------
elem=C,N
organic
Summary:
--------
Nitrite ion reacts very easily with ethanol in acidified solution to form ethyl
nitrite. The ethyl nitrite easily escapes as gas from the liquid (it has a
boiling point of 17 C). The gas can be ignited and burns with a grey flame.
Description:
------------
Take approximately 1 ml of ethanol and mix this with dilute sulphuric acid
(appr. 2 M H2SO4): The liquids easily mix and a clear and colorless liquid is
obtained.
In a separate test tube, dissolve several 100's of milligrams of sodium nitrite
in 2 ml of water.
Heat both test tubes with your hands, such that the liquids are luke-warm.
Slowly add the solution of sodium nitrite to the solution of ethanol in dilute
sulphuric acid: As soon as the solution of sodium nitrite reaches the acidified
solution of ethanol, there is vigorous bubbling and a colorless gas is
produced. This gas has a faint sweet odor, not unpleasant.
Keep a flame near the open end of the test tube: A small grey flame appears and
is sustained.
Add a few more drops of the concentrated nitrite solution, while the small
flame still exists: As soon as the drops of nitrite solution reach the
acidified ethanol solution, there is vigorous bubbling and a larger flame
erupts from the test tube. The flame is pale orange, due to the presence of the
sodium ions. When the flame becomes smaller again, the color changes to grey
again.
The liquid in the test tube also becomes somewhat turbid. Small oily droplets
of liquid are dispersed in the liquid. When the liquid is shaken, then small
bubbles escape from the liquid and the flame at the open end of the test tube
flares up somewhat.
----------------------------------------------------
In this experiment it is shown that the nitrite ester of ethanol is formed very
easily and if the liquid is somewhat warm, then this easily escapes as a
colorless gas.