Experiment 3.5

№ experiment

Description of the experiment

Place 1 ml of 0.5N potassium iodide solution, 7-8 drops of diluted sulphuric acid into a test tube and add 4-5 drops of 0.5N sodium nitrite solution. 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

№ experiment

Description of the experiment

Place 3-4 drops of concentrated nitric acid into each of two test tubes and add: a piece of copper shaving into the first tube, a piece of tin into the other one, close with a stopper provided with an exhausting tube and heat. What can you observe? When the air will be superseded from a test tube, pass the gas which evolves in a test tube with water, and add 1-2 drops of litmus neutral solution to it. What can you observe? Give the equations of the relevant reactions and make a conclusion on chemical character of nitrogen (ІV) oxide.

Observations

Equation of reaction

№ experiment

Description of the experiment

Place 1-2 ml of concentrated hydrochloric acid into a test tube and add 4-5 drops of concentrated nitric acid. What can you observe? Put a strip of filter paper, moistened with solution of potassium iodide to an aperture of the test tube. What can you observe? Give the equations of the relevant reactions.

Observations

Equation of reaction

№ experiment

Description of the experiment

Put one microspatula of crystalline nitrate of potassium, manganese (ІV) oxide and potassium hydroxide into a dry test tube. Heat the test tube until mixture melts. What can you observe? Give the equations of the relevant reactions.

Observations

Equation of reaction

№ experiment

Description of the experiment

Put 3-5 crystals of copper (ІІ) nitrate into a dry test tube. Heat a test tube until mixture melts. What can you observe? Give the equations of the relevant reactions.

Observations

Equation of reaction