3. Chemical properties of oxygen compounds of nitrogen
Experiment 3.1
№ experiment |
Description of the experiment |
|
Put 2 g of the crushed ammonium nitrate into a test tube, close with a stopper provided with an exhausting tube and heat cautiously. Do not heat salt above 170-180°, because in this case the mechanism of reaction is changed and other products are formed. The reaction proceeds with self-acceleration, therefore when reaction is accelerating it is necessary to reduce or stop heating temporarily. When air will be superseded from a test tube, collect the gas, which evolves in a test tube by a method of air replacement. How is the test tube to be placed? Put a decaying splinter into a test tube with gas. What can you observe? Does it support burning? |
Observations
|
|
Experiment 3.2
№ experiment |
Description of the experiment |
|
Put 0.5 g of copper shaving into a test tube, add 2-3 ml of diluted nitric acid, close with a stopper provided with an exhausting tube and heat. When air will be superseded from the test tube, collect the gas, which evolves, in a test tube by the method of water displacement. Open the test tube with gas on air on a background of a white paper. What can you observe? Close the test tube, overturn it, load in an exsiccator with water and open under water. What can you observe? Add 1-2 drops of neutral litmus solution to the solution in the test tube. What can you observe? Give the equations of the relevant reactions. |
Observations
|
|
Equation of reaction
|
|
Experiment 3.3
№ experiment |
Description of the experiment |
|
Place 1-2 ml of sodium nitrate solution into a test tube and add 5-6 drops of diluted nitric acid solution. Why is the solution discoloured? What gas is collected over the solution? |
Observations
|
|
Equation of reaction
|
|
Experiment 3.4
№ experiment |
Description of the experiment |
|
Place 3-4 drops of 0.5N solution of potassium dichromate, 5-6 drops of diluted sulphuric acid into a test tube and add 4-5 drops of 0.5N solution of sodium nitrite. How and why is the solution discoloured? What properties does sodium nitrite show in this reaction? Give the equation of the reaction. |
Observations
|
|
Equation of reaction
|
|