Make up the equations of the reactions

K + H₂O =

Na + H₂ =

Li + N₂ =

Li + C =

KO₂ + CO₂ =

KOH + O₃ =

KO₃ + CO₂ =

Na₂O₂ + Na =

NaN₃ + NaNO₃ =

K₂O + H₂O =

LiOH

NaCl + C + CaCO₃ =

NaCl + NH₃ + CO₂ + H₂O =

Li + O₂ =

Na + O₂ =

K + O₂ =

Na₂O₂ + H₂O =

Na₂O₂ + CO₂ =

KO₂ + H₂O =

Experimental section

1. Materials and equipment: metallic sodium, crystalline sodium peroxide, solutions of phenolphthalein, sulfuric acid, potassium iodide, lithium chloride, sodium chloride, potassium chloride, porcelain casserole, porcelain crucible, glass funnel, test tubes, microspatula.

Chemical properties of alkali metals

2.1. Receive a small piece of sodium from laboratory assistant, dry it with a filter paper from kerosene (it is usually kept under layer of such non-polar organic solvent), and place it in a crucible. Heat a crucible in the ventilating hood. What is it observed?

After cooling transfer the contents of the crucible with the help of a microspatula to a test tube; add 5-6 drops of diluted sulfuric acid and 2-3 drops of 0,1 N potassium iodide solution. What is observed? Give the equations of the relevant reaction.

2.2. Place some water in a porcelain casserole. Receive from laboratory assistant a small piece of sodium, dry it with a filter paper from kerosene, throw it in the porcelain casserole and cover with a glass funnel. What is observed? After completion of the reaction add 1 drop of a phenolphthalein solution to the solution in the cup. What is observed? Why? Give the equations of the relevant reaction.

2.3. Put 1-2 microspatulas of crystalline sodium peroxide into a test tube and add some water. What gas evolves as a result of the reaction? How it can be proved?

2.4. Take nichrome wire with an eye on the end, wash it thoroughly in a solution of hydrochloric acid then put it in a solution of lithium salt and bring to a colourless flame of the burner. What can you observe? Do the same with salts of sodium and potassium.

Laboratory work 4

S - ELEMENTS of ІІ GROUP

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